I had my 84 Camaro sitting for a month and now I start it up the trannsmission does not have any power when I floor it takes a while for it to speed up I, checked the fluid and it's ok but when I hit 25mph it sounds like it wants to die out

 

does it down shift when you pull the shifter to 1st?? (maybe 2nd or 3rd gear start)

does passing gear work?

do all the gears work??

if so, sounds like the torque converter one way roller clutch is broken. will take a new converter.

make sure your parking brake isn't stuck on, too. wiggle the cables, make sure the rear wheels spin free off the ground in neutral with the engine off.

....lots of possibilities

 

All gears work

 

my educated guess is the torque converter took a dump. time for new one.
check the filter, cut it open, if there's more than just a teeny amount of junk in it, time for an overhaul and new converter....

 

Replace your 700r4 with a 1987 or newer one b/c many uprages were added by gm to improve the performance of the 700r4. Thats what I would do considering that the 700r4 before 1987 were weak.

 

or, if you know what you're doing, (professional), you can change the internals in the right combinations, to match the 87 and up.
I have done it many times.