i bought a keyboard..want to take up free online classes

I'm not an expert, but I might be able to offer some advice. Have you considered going to your local Goodwill, or other secondhand store and purchasing some old books. They are usually only about a quarter a piece. A lot of times they have beginner books there, all the way up to just different music pieces. If you would like to learn to play the basics, I think this would be a great way to learn. Another thing to consider, once you have learned a few things, is to record yourself. It is always easier to catch any mistakes when you are playing it back and listening, rather than trying to listen and play at the same time. Good luck to you! I hope you do well!