It seems that by moving my slide on my trombone (not an expensive one), I cannot get my instrument to change pitch/sounds/notes. Regardless of where my slide is in whatever position, all notes sound pretty much the same unless I change my embouchere. Still the notes all are pretty close in pitch. Can you help? Thanks.

tg

I'm going to assume you don't have a trombone teacher, since a teacher would be helping you with your problem(s).

Are you able to take the mouthpiece out of the horn and buzz the notes on the mouthpiece? Can you buzz a simple melody (just) on your mouthpiece? For example, try to buzz "Twinkle Twinkle Little Star." Can a friend, sibling or parent recognize the tune you are buzzing?

What makes the pitches change is you. The way you form your embouchre (lips, tongue, etc.) provides the vibrations which start the sound. Your trombone just amplifies those vibrations in particular ways based on how the trombone is constructed.

Without hearing and watching you, it's impossible to help you figure out what you are doing. You really should make an effort to find a teacher you can go to who will help you work through this to improve your playing.