Key does not work

So this is in regards to my boyfriend's car. He has a 97 Pontiac Sunfire, and we have the worst trouble trying to start the damn thing.
I think the issue is that the key is so worn, so it isn't hitting all the pins right to turn the thing.
A friend suggested that a new ignition was what we needed. I feel like that might fix it, because we went to our local hardware store to get a new key, but that didn't do anything. It just made a copy of a very small key that doesn't work.
I am not really able to take it to any kind of mechanic because we literally cannot start it. And I'm pretty sure nobody else will be able to either. Needed gas in it one day and we had a really humiliating time getting it started back up at the gas station...
Any help would be appreciated!

Need a better description what happens when you turn the key. A no start could mean it cranks but does not start or you turn the key and nothing happens.

Can't turn it at all.

Can't turn it at all.
If the steering wheel isn't locked, then your are probably right that the key is worn. You could call a locksmith or dealer to ask about cost about getting a key cut using the VIN number. Not just a copy. If the key actually looks worn out.

I agree with the Cat.....First thing to do, is bring your registration to prove ownership, and have a new key cut, not traced......compare old key to new key, should be essentially the same, just worn...if not close, somewhere along the line, the key and lock cylinder have been replaced.....

If the new key looks similar to the old one, see if it turns the lock cylinder....if it doesn't, wiggle it and attempt to turn, it might eventually turn....but you will still have problems.......your problem is the tumblers in your lock cylinder.......it's easier to replace the lock cylinder if you can turn key by wiggling it.....if you can't turn the key, then it becomes more involved and you will have to drill the lock cylinder out.....special procedure.....

Long shot but spray some lubricate into the ignition.