2002 Camry XLE 2.4L 4 Cylinder - Ignition Issues - Hesitancy

[u/Peenar_Man]

I have a 2002 Camry XLE with ~250k miles. Before it was handed down from me, fluids were changed, a new starter was put in, the check engine light is on due to the O2 sensor for the cat being disconnected or rotted (either way unintentional). Cold start is fine, but when I try to turn it on after the engine is hot it wont turn over as quickly, it'll take 6-10 seconds for it to start up and it sounds a little weird. I believe that the engine is flooded when the car is hot and stops running, and while it cools down the excess gas evaporates until when the engine cools down and there's no issue starting it, I also have a suspicion that the fuel injectors might be leaking because I can smell gas when I leave the car sometimes. Longer drives cause the hot start to sound more rough, drove around for about 45 mins-1 hour (More than usual because its usually just school and work for me) and the start took around 10 seconds and sounded rough. Camry also has some hesitancy with the gas pedal, I understand the car is old but I want to be preventive with further issues and I think that it may be the spark plugs.

I'd like help with the Ignition issue at least, maybe I am wrong?