First thing I would say is what do you mean by hobby?
Like spotting, watching, volunteering at a preserved or heritage railway, or railway modelling?
Reason i say is because if you're talking about a career in the rail industry, that is very different from a hobby and you should never treat the two as the same when it comes to the Rail Industry. It can be dangerous and many people have messed up because of it.
Having a passion for the industry you work in is something else entirely and that is great
Many of us here have that. But a hobby shouldn't be working in the industry, if that makes sense.
So tell us about what you'd like to do and where