Temp rises when I’m in traffic

2 months ago I bought a Pontiac g6. Within a
few days my engine was running warmer than
it should. I took my car to a mechanic and I
needed to replace the radiator, temp sending
unit, lower radiator hose, purge hose from the
coolant tank, coolant tank, and thermostat. I
finally got my car back and I’m really paranoid
about any little thing. Last Friday on my way
to work I had gotten a coolant flush, and oil
change after that I decided to grab me
something through a drive thru, I was waiting
in line and my temp bumped up in between
normal temp and 225 so I panicked and drove
off once I was going 20 mph my engine was
cooling off I parked my car at work and I
waited 3 minutes to check the engine temp I
twisted my key to the notch before your car
cranks and it showed 230... I was trying not to
think about it so once I got off at work I
checked the fluid my it was under the line so I
topped it off. I made it home everything was
fine so I turned my car off and checked the
temp 3 minutes later agin but my temp was at
225. Yesterday I was just starting it up and
everything seemed good I went to the store in
a Uber so nothing would happen to my car,
once I came back there was a little spot of oil
and a melon size spot of coolant I guess? On
my passenger side of the engine I haven’t
noticed any leaks or anything! I’m lost I need
help! Between college and work it’s hard to
save and advice would be appreciated!!