Ahhh ok.
First, start with checking for any leaks.
Inspect all the lines, fittings, calipers and wheel cylinders.
Also carefully inspect all the flex hoses, if there is a faulty one it mat swell up when the brakes are applied causing a soft pedal.
That would be a 2 person job, one watching the hose while another applies the brakes.
Yes you’ll need to remove the wheels and brake drums.
While your in there you can also check the pad / shoe wear and R&R if needed.
If that all checks out good.
You need to ask when was the last time or how long has it been since the brake fluid was changed.
If you can’t remember, or it’s been several years, you may want to consider flushing it all out with fresh fluid.
There are YT videos showing how to do a single person gravity bleed.