98 cavalier will crank but wont start

Now I have been told by a lot of people the things it might be:

because a friend cut the original wire harness from the radio people said it might interfere with my ignition

crank sensor

fuel pump

The relay is good. The fuel pump hums when the key is in the on position. I tried starting fluid and it did the same thing. Some say they don’t think its the fuel pump. and a fuel pump is extremely expensive so I don’t want to replace it if I don’t have to. Someone told me bout a fuel pump switch to reset it but I cant find it. It was not in the trunk. So I have no idea where it is if I even have one.

Any one have any ideas of what to try or what it could be and how do I know what it could be. It wont start so I cant take it to a shop or somewhere to have it looked at.

AHHHH Please help me!!!

If it does not start with fluid, if fluid was good? It would be no spark or spark at the wrong time or no commpression.
Timing light or spark checker will tell you if you are getting spark.