One of the most difficult things about starting up in photography is, unless you have a considerable amount of funds to start with, you won't have all the lenses you probably want. To be honest, even the most basic camera is probably sufficient for most amateur photographer’s needs. However, it is the lenses that really make the difference.
Cameras go down in price the second you buy them, but lenses aren't the same. They can be used across numerous camera bodies. The lenses that attached to the first Canon 5d still work on the Canon 5d mark 4. The downside is that even used lenses are pretty expensive. If you want a fast portraiture lens, that's $1,000 bucks. You want a long range wildlife lens? That'll be $2k. Before too long, photography turns into a bank account diminishing proposition.
So what to do?
Buy vintage glass!