These are the fundamental notes and positions you need to learn.
This slide position chart shows where the bar of the outer slide should be in each position. The top line is valid for all tenor and bass trombones, the second line for all bass trombones and tenor trombones with an F-attachment, and the last line is only for bass trombones.
Ths notes that are commonly played in each position without any attachments engaged are as follows: 5 y
1: B♭, F, B♭', D', F'
2: A, E, A', C#', E'
3: A♭, E♭, A♭', C', E♭'
4: G', D, G, B, D' (alt)
5: G♭', D♭, G♭, B♭' (alt), D♭' (alt)
6: F', C, F (alt), A' (alt), C' (alt)
7: E', B, E (alt), G#' (alt), B' (alt)
7: E2/Fb2 B2/Cb2 F#3/Gb3 C#4/Db4 G#4/Ab4
6: E#2/F2 B#3/C3 G3 D4 A4
5: F#2/Gb2 C#3/Db3 G#3/Ab3 D#4/Eb4 A#4/Bb4
4: G2 D3 A3 E4/Fb4 B4/Cb4
3: G#2/Ab2 D#3/Eb3 A#3/Bb3 E#4/F4 B#5/C5
2: A2 E3/Fb3 B3/Cb3 F#4/Gb4 C#5/Db5
1: A#2/Bb2 E#3/F3 B#4/C4 G4 D5
You should notice a pattern.
Some trombones include an F attachment. The attachment makes the instrument the equivalent of 5 positions longer when the trigger is activated. This allows the player to play 6th position notes in 1st, and 7th position notes in 2nd. The trigger can also extend the range of the instrument by allowing the player to reach lower notes than usually possible by using the trigger beyond 2nd position.