There is already so many answers so maybe you won’t even read this, but the main point I think is just start, this is not valid only for self hosting but for any project. Just start doing something, anything and the path will draw itself. Doesn’t need to be correct or perfect, it just needs to be started. Maybe you can start with the old laptop. Have you tried linux yet? Try it because that will be a basis for your self hosting. Just get the vibe, use it for a while, install shit on it. Go through tutorials. Maybe you realize it would be cool to try and host a simple website on it, just for funzies, just on the local network, you will learn so much on it and half way through you will have a dozen other ideas… I know this advice may be vague, but just go with the first thing you see and you think to yourself “this would be cool to have/do” 😊