Patt 38 and M1???

On a pattern I’m using, I’m doing the large version and it says “keeping basket weave pattern correct, and starting from the 5th row of the pattern (which is p5 * k2, p6, rep from * to last 4 stitches, k2, p2) patt 28 (32,36) ((for me 36 because I’m doing large)) sts, M1, k2, M1, patt to end.

Does this mean I follow the pattern for 36 stitches, then M1, k2, m1 Then finish by following pattern? And what is M1???

Welcome to the forum!
M1 is make one, an increase.

Yes, follow the pattern for 36sts, M1, k1, M1 then pattern to the end. Watch that the pattern on this row follows the pattern in previous rows and doesn’t shift.
What pattern are you following?