Ran out of gas now I have a p0300 code and car runs really sluggish 04 envoy v6

several things possible,one being clogged injectors from running the fuel tank dry and sucking up all the trash in the tank to the engine.you should NEVER get below 1/4 tank,consider that as empty and re-fuel or sooner than later you will burn the fuel pump up and that could be costly! copy and paste the link below.... https://www.autocodes.com/p0300_gmc.html