What he said ^.
Gasoline or LP? Presume gasoline.
Does it start and run 15 sec repeatedly or was it one and done?
Blue smoke is oil.
Not necessarily an issue. Could be from sitting, could be burning a little oil but still ok.
A lot of people don’t even notice, but most engines, new or old, in my experience, will blow a little blue smoke on startup. Once in a while. Could be a chunk of carbon holding a valve slightly open, sticky ring that frees itself up or any other number of things.
If it does it every time cold and then clears up, likely worn top end valves etc. if it smokes after warmed up and constantly then likely rings.
Is the crankcase over full ( gas draining into case, stuck float on a gravity fed, primer stuck on and you didn’t notice etc)? If so it could be sucking in diluted oil. Could also make it not run right, maybe.
From there, could be carb plugged up
Need more history and symptoms.
Old gas, sat for a long time?
Original question is it repeatable runs and dies?
If no restart, does it fire on ether?
Is the fuel pump working consistently? Did you check it?
