The internet offers a many sources for you to expand your knowledge; a lot of it is free so take advantage of it!
One of my favorites is www.udemy.com! You will find many inexpensive courses and there are some that are free so check them out!
This is an endorsement that is unsolicited! It is strictly for your benefit; I do not receive any affiliate fees so take advantage of it!
I continue to say that the best investment you can make is in yourself and your knowledge.
Just do it!