Below are videos taken from YouTube that will help with your playing

​belwo is the best video on buzzing. please do as he says and do the 1 minute a day exercise too!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

thsi video shows how to make proper embrochure (mouth shape) to get good sound from a trombone or baritone

WATCH THIS....it is about your air stream which creates good tone

here is more on blowing into the trombone, and the first three notes : d, c, and b-flat

​the video below has a great fingering chart that shows all the notes a trombone can play

​here is a reference for reading the lines and spaces on the bass staff;

notice that I said 'reading lines and spaces"  NOT  "reading notes.

this is because it is the lines and spaces that are named : A,B,C,D,E,F,and G. The notes themselves are actually named only for the amount of time they are held for :
quarter note = 1 beat
half note = 2 beats
whole note = 4 beats
and so on. 
IF YOU SAW THE HEAD OF SQUIDWARD ON THE BOTTOM LINE OF THE TREBLE STAFF, YOU WOULD PLAY AN   'E'. I don't know how LONG you would hold it for, but it would be played as  'E' because ANY note symbol on the bottom line of the staff is played as   'E'

​and this video might help you with playing high notes;