Playing under someone more experienced can build confidence, but the only way to learn how to run a ttrpg is to start running one. Find some one page RPGs with really simple rules that can be learnt in a few minutes and played over an hour or two. No one has to invest in anything, you can switch between different ones to find what people like, and there's no pressure to keep running a campaign if you find it too much. Once you have an idea of what it's like running a game you and your friends can decide if you want to play a long adventure.