A good beginner Bach piece is Minuet in G
Tab:
https://tabs.ultimate-guitar.com/tab..._g_tabs_189404
Bourree in E minor is another old favourite, maybe a little trickier:
Tab:
https://tabs.ultimate-guitar.com/tab/189037
This was the one that Paul McCartney and George Harrison learned (at least in part) as teenagers, and was the inspiration for Paul's Blackbird, and probably (more indirectly) Yesterday too.
Oh yes; sorry, but you
have to learn standard tuning! Seriously, bite the bullet and get down to it. There are players who find other tunings more comfortable and stick with them (such as DADGAD or EADGCF) - and two or three geniuses who invented a whole raft of bizarre alternatives (Joni Mitchell, Nick Drake). But you will then have your work cut out transposing pieces like this to your chosen tuning. You will be in your own little ghetto.
Alternative tunings are great, but it's a mistake IMO to get stuck in any one. Just as I would never suggest anyone get stuck with EADGBE!