New to Ford, 5 speeds, and trucks

Hey, I just bought a 92 F150XLT standard cab, short bed. 4x4, 5 speed, 5.0L with a 4" lift. I paid next to nothing for it and bought it to play around with. Never had a Ford before, always been a GM guy. I can definately tell a difference, but not sure if this is good or bad. Just different I guess.

I am new to manual transmissions in general. The only one I have driven was a geo metro a friend of mine has. I am having difficulty getting it into reverse from time to time. I am sure it is something stupid I am doing, but wanted to make sure. I can get it into reverse if I moved through a couple other gears first, but most of the time if you go to put it in reverse you either can't (feels like you are hitting a wall in the gearbox) or it grinds. Obviously, this is with the clutch in.

Ideas?

Thanks.