95 Grand Am help

So I have my Grand Am in the shop for a week or so and I finally get it back, but I drove it around last night and stopped for gas and the engine was acting like it wasn't going to start, which sucked cause I was in an area where the gas station attendant was behind bullet proof glass. I kept trying and get it to start after four tries, then the guages kept jumping the whole way home. My buddy that worked on the car said he had drove it around for awhile and had no problems. Any ideas? Thanks

I drove the car around again today and had no problems until I got home and then the car wouldn't turn over, again it took numerous tries to get it started but the gauges were not jumping which is good I guess.

This seems to be a random problem and I can't figure out what it might be. Could it be a problem with the power supply to the starter? and if so why would the gauges have been jumping?