Very common question. Before you do anything you’re gonna want to adjust valves and pull the carb and clean it out well, and check for an intake boot tear, VERY common for these. You won’t notice a crack unless you physically pull the boot between the carb and head off and inspect thoroughly. Also start with a nice clean air filter. When you get it warmed up and it stalls, I bet if you pull the hot start it’ll start right up. Just from what you’re saying I bet if you go down one or more on your pilot and re-adjust fuel screw you’ll be golden. People jet these bikes half warm, when you start a cold bike you need more fuel, that’s what the choke is for! Then you end up super rich when the bike is all warmed up! I wouldn’t suggest stock jetting. I don’t have experience with these bone stock, but everyone tells me how bad the stock jetting is. You could also have a restriction somewhere in the intake, or maybe you just simply left the choke on haha.
The choke is the black knob, the hot start is the red one above it, little hard to get to. Good luck!