
You have one leg trapped. Flatten them with a crossface and underhook, then free your leg and pass.
From the top of half guard you are halfway past the legs. Finish the pass and you score 3 points and reach side control or mount. Your opponent will try to get on their side, take the underhook and sweep you.
Win the upper body first: crossface, your own underhook, chest heavy on theirs. A flat opponent can't sweep. Then free your trapped leg with a knee slice, a backstep or by walking it out, and settle into side control before you look for anything else.