2002 pt cruiser

I have had my 2002 pt cruiser for 4 1/2 yrs
now has 138,000 miles on it had no majors
problems until recently.1-dash lights went
out but not all of them its not fuses-2muffler
pipe broke i replaced with new pipe an
muffler but has a lil air slipping out in
between two clamps cuz i needed extra pipe
fitting i put sealer glue around pipe much
better an had a guy tighten clamps but still
leaks on edges what do u suggest 3-auto
parts store said ac compressor wasnt engaging the blue light when i turn ac on
doesnt come on anymore checked fuses idk
my dad added two cans of 135a didnt last
long i didnt believe autoparts store so i
added one can 134a cold but bot as cold as
its use to so i bought sealet with coolant an
added haf uv dye in it to tell me mt leak was
a bolt on top of compressor so far so good
but should i mess with bolt now since sealer
is in it? 4-my water temp reading low added.
Coolant to resevoir already had some in
radiator cap so coolant in resevoir spilled
out on driveway thought i had a leak so i
added water to watch it again come out but
then water stayed in next day water temp
was low so resevoir empty again an radiator
cap still having coolant in it autoparts store
added water to see leak but it didnt leak now
what?its not overheating at all yet