How does anything get fully completed on-time?

neither of the teams I have worked on Scrum with have been able to accomplish things on a predetermined date

The only "predetermined date" you have in Scrum to finish something, is when the Sprint timebox runs out.

So, define a sprint length (i.e. 4 weeks) and you have a predetermined date (2 weeks from now) when some things are Done (namely, the product incrtement derived from the sprint goal)

How does Scrum solve for a completed project on a specific date?

It doesn't!! Scrum is a framework for incremental product development, not project management! If you want this, it may be much better to use an other (project management) approach!

I am trying to get my head wrapped around how Scrum finishes projects without spending $1500 for a professional training I do not want

I would argue it would be 1500 well spend, because I do think there are a lot of scrum fundamentals to be learned here. Going to and through the WHY of scrum

Can you be more specific with your questions? Xander's response once on point.

How does Scrum solve for a completed project on a specific date? The organization and work acceptance just seems really random.

Do you conduct Sprint Planning and discuss what you want to accomplish within the sprint (No longer than 30 days)?

Why do you feel that it is random? Has your PO ordered the backlog at all?

 neither of the teams I have worked on Scrum with have been able to accomplish things on a predetermined date.

Why do you use "completion date" as a measure of your success instead of actual value? You mentioned you are working on advertising/web so I am wondering if you used techniques like A/B testing to determine the response of your customers? Have you received positive responses from your SEO strategies?

If your company has committed to Scrum, you should advocate (talk to HR) for them to sponsor a Scrum Trainer to conduct Scrum training for every member of the team. What you are experiencing is quite common. The decision to "go Agile" is forced on business units by company leadership without the team members being trained on the framework.

If things are appearing random, talk to your Scrum Master and ask the Product Owner to talk about the Product Vision. The work and the goals should be visible to everybody on the team.

Ken Schwaber once said: "Scrum is like your mother in law, it points out all your flaws (or mistakes, I don't know the specific word, wasn't there)". And I think that is how you could treat this specific situation. Use it as a valuable opportunity to figure out what's going on in the organization and how you could improve. This is the perfect example of creating transparency, inspect and adapt. Scrum does not finish projects, people do. Scrum is just a framework that helps the people finish stuff. Actually finish, not half-finish.

Besides that, I can really recommend attending one of the courses. You learn so much more than you would think.

I have worked on Scrum with have been able to accomplish things on a predetermined date. How does Scrum solve for a completed project on a specific date?

@Luke Reed, I understand how you feel being new to Scrum and I believe even I had the same questions in the earlier days.

Here's the thing, Scrum does not tell you how to do things, rather it minimally prescribes certain things that should be in place so that the focus of a Scrum Team is to deliver potentially releasable "Done" Increments of Product. This is the essence of Scrum.

If you have a project that you should complete by a specific date, then do other traditional approaches work better? Scrum cannot guarantee that you will finish your project on a specific date. If there are issues that are preventing progress, then unless those are removed your date of completion is likely at risk no matter which way of working you choose.

Hope this helps.

How does Scrum solve for a completed project on a specific date? 

Completing something by a predicted end date simply shows that you are adept at finishing work by a chosen target date.   It says nothing about the quality or value of the product being delivered.

The Scrum framework is about building the right product through frequent inspection and adaptation events.   It is not about solving the inherent difficulties associated with "following a plan".

 I am currently working on my second team that is organized in a Scrum format and neither of the teams I have worked on Scrum with have been able to accomplish things on a predetermined date. 

Scrum won't do this by itself.  Scrum provides a framework that helps a team iterate towards a solution by making changes along the way to adapt to the users' feedback.  The key is the word iterate.  The teams should not be delivering everything by a specific date.  They should be delivering usable parts of the solution incrementally. Show it to the stakeholders/users and get feedback on what to do next.  In the end, the solution that is delivered will be what the stakeholders/users really need and it will be delivered when the stakeholder/users say it solves their needs.  Using various techniques, which I will not go into now, you can forecast approximate dates for delivery of solutions.  

You are still viewing work from a project management style of "I will pay $$$$$ and you will give me some thing on MM/DD/YYYY".   In an agile environment it is more along the lines of "I will guide you to what I really want while paying you $$$ every ## days when you show/provide me usable portions of my solution."  In the second case it may turn out that the number of $ signs could be more or less than a standard project management approach. But the real win is that the customer gets what they really need and are included in the process along the way.  Old project management has over the years frequently resulted in money spent to get something that was needed at the time requested but because of changing needs, it is not longer the right solution.

Hope that helps. It is a very high level description because the answer you seek is not easy to do in less than a 1000 words.  

It just occurred to me Luke that you may benefit from the Pizza Hut / Subway analogy discussed in the following two threads:

https://www.scrum.org/forum/scrum-forum/29009/regarding-hybrid-agile

https://www.scrum.org/forum/scrum-forum/16922/agile-and-scrum