Trying to align 65 coupe doors after painting. Weather stripping not sealing front of both doors. Should i take it to a body shop or do it with help?

Well you didn't specify where it's showing up in the vehicle if its the trunk make sure the trunks weather strip and seal that goes around the body and seals when the trunk is closed is not broken and also the trunk has seam sealer for the body joints and welds make sure theres not even a pin hole in it ,a leak can also be coming in through the windshield fr/rr from the sealer under the glass getting brittle in the front there is a cowl screen that keeps out leaves and other debris and it has a rubber gasket on it this can dry up and break and this applies to water only if you see antifreeze it's your heater core unless your using straight water forengine cooling which you shouldn't be another leak spot is all the doors insulation rubber and the window strips if they are severely worn water can run down freely into the doors and from sloshing around inside can drain into the passed compartment from a rust door skin on the bottom

Try checking the seals. If they are cracked or pieces missing. That will cause leaking.

is the water leak allowing the water to wick up into the headliner or is the headliner getting wet without water coming past the weather stripping around the door?

If it is wicking then fix the weather stripping.
If the water is getting headliner wet with out passing the weather stripping then you have a leaking sun roof.

You can the door seal by sitting in the car while you have some spray water (garden hose) gentle at the frontal and upper door seal.
If not leak there inspect seal of sun roof and real seal with correct type of sealant.

Check and make sure seals are even not warped. Check for rust around the are where it's leaking. If you have a compressor with a blow gun blow along the area where the water is leaking in. If you feel air coming through the area check and make sure the weather stripping is sealing properly. Doors could be out of alignment as well causing the leak. Or door seals could be rotting out.

you can 'fish' a coat hanger through the door seal to press the unlock button on the armrest, or slide down along window into the door's body to attempt to manually work the locking mechanism... a slim-jim is helpful here but can be done w/ coat hanger. WARNING!: this may damage your paint or the door seal or both, or the window seal.... once in the main body of the car...trip the lever

depending on what type of vehicle you have this could be an easy fix.
if your vehicle has a frame around the window, then the frame may be
sprung. roll the window all the way down, open the door, let the bottom inside of the door rest against your leg, then grab the frame at the top and pull it inward toward the vehicle. this will spring the frame back inward and help seal it against the weatherstripping. hope this helps....

i have bent many doors to make them fit.Roll down window and door should bend fairly easly,keep checking with that buck

Some leaks actually are from the windshield and it is contained by the trim so you can't see where it is leaking from. If it is the door seal look at the striker bolt to see if there is any abnormal wear. Make sure the striker bolt is aligned with the door striker. If you don't know how to check this run by your local body shop and ask them to check it for you. Sometimes if the keys have ever been locked in the vehicle people use door shims to hold the door open as to pick the lock. This is bad because it knocks the door out of alignment with the seals. Hope this helps.

Sure. Use bondo. Do you have a paint sprayer?

Most composite bumpers have the paint in the composite, but I dont' know why, at least for a coupe or three years, the bumper wouldn't hold paint sprayed on.

I don't think you can hurt it by sealing it from the outside. Your issue is the inside of the frame. The pillar is not airtight. Most of what you can use will smell for years if you spray WD 40 inside to displace moisture.
You might consider taking it to All-American car franchises or equivalent. They drill and plug body areas routinely to spray inside door panels,tailgates,etc. It would inhibite rust and unless you actually replace the metal when you want to paint the car, theres not much else you can hope to do. I live in the Michigan rustbelt area.