Developers personal development

I'm assuming that you are a Scrum Master. If not, ignore my response.

Treat them like everyone else in your organization and don't single them out.  They should be part of a self-managing, self-organizing team that can support them in their professional growth.  Do your part to help them understand the Scrum framework and how it helps organizations and individuals be better at adapting to change.  Help them learn the benefit of empiricism because it can help them in more than just working on items from the Product Backlog. 

Professional growth is largely the responsibility of the individual trying to grow.  Let them ask questions as they have need.  Listen and be there when there is something you can provide them when they ask.

So, on our team we have some entry level developers (primary front-end). How could I help those developers with their personal development and coach them in scrum with the rest of the team? Thanks!

Exemplify servant leadership to them, and encourage them to find new and innovative ways to be of better service to others.

Make sure that there's capacity in the Sprint, probably for several Sprints, to give time for personal development and coaching. When planning your Sprint Goal and selecting items from the Product Backlog for the Sprint Backlog, work with the Product Owner to help manage expectations and give the team room to grow and develop. Taking on a little less work now and giving time for this development can help the team be much faster in a few Sprints.

Thank you all for your comments and suggestions. Yes, I am a Scrum master. One of the impediments  we are working on is bringing the culture and environment that influences self-organization and being cross-functional. Our organization and team have a lot of moving parts. So it’s a struggle at times but I’m pushing as best to coach on what and how to use Scrum.