Barre chords utilize open chord “movable shapes”. These are the open chords E, A, and C and their relative minors, sevenths, etc.
Play an E chord (022100) using finger 3 on the A string, 4 on the D string, 2 on the G string, and finger 1 as the barre (which isn’t fretted in an E chord so just don’t put your 1st finger on the fretboard). Slide that shape UP one fret and then barre across fret 1 with your 1st finger (133211) and you have an F barre chord.
Play an A chord (x02220) using only finger 3 to barre fret 2 on the D, G, and B strings only. Slide that up two frets and use finger 1 to barre fret 2 (the low E string will remain muted so this barre really only needs to affect the A and high E strings) and you’ll have a B barre chord (x24442).
To make the F a minor barre chord, drop the note on the G string down 1 half step just like an E minor chord (133111).
To make the B a minor barre chord, drop the note on the B string down 1 half step just like an A minor chord (x24432).
F Barre Chord
The first barre chord you should learn is the F barre chord. This is a good lesson on just the F barre chord – it shows how to place your fingers, how to roll your barring first finger if needed to reduce buzzing or pain, and covers positioning your hand and wrist: https://www.justinguitar.com/guitar-lessons/the-f-chord-b2-901
E and A Major and Minor Shape Barre Chords
This is a good lesson on barre chords after you’ve learned the F barre chord: https://www.justinguitar.com/guitar-lessons/easy-barre-chords-for-beginners-bg-2303
Power Chords
This is a good lesson on power chords (usually the 133 pattern of a barre chord) and you may want to learn this along with barre chords: https://www.justinguitar.com/guitar-lessons/power-chords-bg-1201