318 hard start when hot

well I brought the battery up to the local auto shop and they told me my battery appears to be fine, good amps, I didn't go back to the back and confirm with them. I also learned that the alternator (or potentially the circuit powering it) appears to be doing nothing. they didn't seem to be able to help me with the starter. I bought a mini starter and will be attempting to change that out as soon as there's a day above 10f here, hopefully in a week or two. any leads as to how the alternator circuit works? or just assume it's the alt itself and switch that as well. I really am like, super broke, so any free resources I can get at this point are super helpful, I can't afford a 100 dollar book that may or may not tell me how to fix things goes.