When I started playing, barre chords were a painful experience to be avoided. But I knew a tiny lady (4' 10") with tiny hands who had no trouble. She said sit classically. Cross left leg over right, keep machine heads level with left shoulder, keep elbow away from body so that forearm makes a right angle with the neck, thumb behind neck parallel with frets, fingers naturally fall in right places and it don't hurt. True!

Callouses necessary when learning because learner hasn't yet learned gentle touch. Should disappear over the years.

Get a guitar to learn with that plays easily. A good guitar sounds better than a cheapo, but does not necessarily play easier. All guitars need to be set-up properly. Low action often sacrifices a better sound for ease of playing (high action sounds better). Don't buy a second-hand guitar without good advice. Teachers often sell the best all-round deals to beginners - they want you to come back for lessons, so they won't rip you off. OTOH you won't get a bargain this way because they know what they are selling.