I can only speak from my own experience.
My first SLR was a Zenit E. very capable, cheap and built like a tank! Next I got a Zenit TTL, similar to the Zenit E, same lens fitting etc.
Then I was given a Praktica BX20 (I still use it now and then) it can be had relatively cheaply. Good quality and a good range of lenses.
Then I got an Olympus OM-10 these also go very cheap. For a little more you might get an Olympus OM-1. Both use the same great range of lenses.
Any of these are a good choice for a first SLR. Others may have other suggestions, but I would recommend an all manual control SLR so you learn the basics of photography as you use the camera.