Cheaters

To make a chord you need 3 notes, the first third and fifth. For a Bb major chord this would be Bb, D and F. For a Bb minor it would be Bb Db and F. So just find these notes on the fretboard to get a version that should be easier to play. For example you could play something like 1 1 0 x x x or 1 1 0 3 x x for Bbmaj. For Bbmin you could do x 1 3 3 2 x. Hope this helps.

You can also play most of the notes of the notes of the Bb barre without actually making a barre. Play X 1 3 3 3 X with the index finger just holding the A string first fret, then either mute or miss out that high e string (both muting and missing would be best). This form might help you build strength for that full barre later.

You could also play it as XX3331. It's a common way to play it if you are not yet comfortable with forming barres.

All very good advice. You could also just make this your barre-practicing song. There are two ways to play Bb as barre:

[x 1 3 3 3 1] or variation [x 1 3 3 3 x]
[6 8 8 7 6 6]

The E-shaped one is easier because it is higher up on the neck. Practice this for a week or so, and you'll get it no prob. ANd once you've mastered this one literally thousands of songs await to be played.

There is a song I was given by my instructor (Scargorough Fair) that has a Bb.
The fingering I use for that is XX0331
The Bb in this song is preceded by a Dmin and followed by an F so chord changes with this fingering are pretty easy.

Since we're talking about cheating, you could always change the song to a key that have more friendly chords.