1994 Ford Mustang Many questions

Hi, my car has been sitting the past 4 years barely being driven.. Maybe like 10 times in total over the 4 years. My car battery had to be replaced so i replaced it and even right after it was replaced my car still seems to want to stall everytime i come to a complete stop unless i press the gas, then i can keep it running. I just recently (past couple days) have been driving it but when i went to start the battery had to be charged because once i replaced it, it sat for another 5 months before it was driven.. Is this the battery or maybe the part that charges my battery? Also after a car sitting that long, what are some of the things i should do to make it run better? I put fuel injector cleaner in it once i filled it.. But what else should i do? Also when my clutch is not pushed in it makes a slight squeeking noise.. what could that be? (its done that ever since its been replaced so maybe it needs to be greased??) I just plan on going on a big roadtrip in 2 months so i dont want it breaking down.. I want to fix as much as i can myself then take it into a shop and get them to do the stuff that would be outta my hands. Please get back to me asap. I just found your site and i ABSOLUTELY love it, VERY helpfull.. I will be letting alot of people know about it..