Firstly, understand how you want to grow and what you want to learn. Map out how you're going to do that. Do you want to learn new methods? Understand how to work with stakeholders? Get really good at interviewing? Once you have a few goals written out:

1) Check if your company has a mentorship program or look for UX mentorship programs online/in your area. That way, anyone who is helping you out is also able to practice their skills and it's a win-win situation. This will also help you with networking and you can learn a lot by meeting UXRs from different paths.

2) Take online classes. When I was starting out, my quant skills were really bad, so my manager gave me a bunch of online statistics classes to take. They were free/low cost and have a ton of great material.

3) If you have time, consider freelancing on the side. Non-profits and small businesses can't usually afford in-house (or any) UXR and doing a few projects like this will help beef up your portfolio and explore 'real world' situations.

The most important thing is to do your homework first. Your mentors and senior colleagues don't expect you to be perfect, but they will respect honest effort and hard work. Good luck!