[Too Many Projects]

Front brakes don't need to be costly. So many of these cars are getting aftermarket discs, that there are sets of complete, original, '69 disc brakes for much less money on craigslist and at swap meets. You certainly don't need $1,500 Wilwoods or other such to get the car to stop better than the drums. I have '69 Camaro D50 disc brakes on the front of my '66 Chevelle that work just fine to haul a heavier car than a Camaro down from speed.

As for the engine, it doesn't cost anything to pull the valve covers and look for a loose rocker arm that would indicate a cam lobe failure. A close inspection of the plug wires to determine if one, or more, has become brittle and cracked from age/heat and could be allowing the spark to jump to ground or to another plug wire and fire a cylinder out of order. Just making certain the wires are in the correct order on the cap and to the related cylinder. A very common mistake is crossing #'s 5 and 7. People do that all the time.
If unsure on any of this, take the people offering help up on that and let them. As others have said, letting the car sit for a period of time, just makes it more difficult to find the time to work on it. This isn't just a fable people throw around, there are THOUSANDS of us who have made that mistake and before you know it, 20-30 years have flown by and it is still sitting with flat tires and surface rust all over it.
I am very familiar with not having the funds to do much at one time, but, for now, your time is cheap/free and doing anything on it will keep the interest and desire level high.