i might take up the trombone and want to know what clef does everyone read.
i am mostly a treble clef reader(flute and clarinet)
do you think i should read the bass clef to be a better musician in reading or should i just read treble clef?

Orchestral parts for the trombone are found in bass, tenor, and alto clefs (playing at pitch).

In brass bands, you will find trombone parts in treble clef transposing in Bb.

Unless you're going to be playing in only a brass band you're going to have to read bass clef. I started in a brass band and was taught in treble but now i'm in orchestras and jazz bands etc and i have to read treble, tenor, bass and now i'm having to learn alto (i can read it, but at the moment only very slowly!) The only problem i've found now is that i've rescently started learning piano and now i'm having to relearn bass clef as i now automatically transpose into Bb

Yeh learn bass clef. Treble and tenor (if you use them) go hand in hand anyway - you read tenor as treble, but add two sharps and sharpen the accidentals. Also if you start in bass clef, eveything will be in concert pitch for you, and that will be more useful later on. Alto follows nicely from tenor.

BASS > TREBLE (Bb) > TENOR > ALTO

That is the better way to learn, I did Treble > Tenor > Alto but haven't got anywhere with the bass clef yet lol

Definitely start with bass clef, then tenor, then alto