There is a lot of advice about painting bikes on these forums if you search for it. I think if you have the space and the patience, it can be fulfilling if you're genuinely curious about creating a nice finish on your bike. However, if you're looking for a cheap and easy way to change the color on your bike because it doesn't really meet your preference, you're in for a lot of disappointment. It takes a lot of work to do it properly (and it isn't necessarily cheap), and even then, you will not likely have a durable protective finish like the one your bike has now.
I did want to go through the process and I lucked upon a special steel frame with a lot of rust, so it really needed a repaint to protect it from rotting further. In the end, it looks ok, but it took a very long time for me (spare time comes in bits and pieces), and it already has several scratches. I'm glad I did it this one time, but I would not do it again.