Timing repair

Okay, I had to do a timing chain overhaul on my the car. The guy that did it seemed to have done the internal part correct but at the end just slapped it back together. I have gone through it and tightened nuts and replaced sensors and just trying to get it in safe running condition because it is all I have. So It runs pretty good but Obdi says it’s running too lean. I cleaned the fuel filter and it seems to be better but it just shuts off sometimes. I have not been able to drive a full drive cycle yet. My dad says that I need to have a computer fine tune the computer to dial in the new repair. Is there a way I can reset it at home because I don’t have a lot of money to get ripped off by a mechanic in my town? Especially because I’m a girl and that’s how it works in this town.