First off, welcome to here...
Second, most of us tend not to treat you differently due to your gender. Telling us you are not all that savvy lets us know that we just need to spend a little extra effort to explain things instead of assuming that you are familiar with things.
How many miles are on your car?
How often is maintenance performed? Who does it?
How many keys are on your keyring? If there are a lot, it could be acting like a slide-hammer over every bump. That will eventually damage the locking part (the tumbler) and possibly make it easier for it to rotate when it shouldn't, which would turn the engine off.
When it cranks but won't start, turn the key off, open the door, then turn the key to ON (but not Start) and listen for a click and a gentle "whirr" sound. That should be the fuel pump. If you don't hear it, try asking a friend to turn theirs to ON while you listen for it. Then you'll be more aware of what you're listening for. Also, while your car is acting like it should, start listening for the pump before each time you start it so you will have it in your memory for those times it doesn't start.
If the pump does not whirr, then it could be a fuse that is intermittently making/breaking contact (from burned or corroded terminals), a bad relay (which actually provides the power to the fuel pump), or a fuel pump that works only sometimes. It could also be damaged or chafed wiring or a plug connector for the fuel pump.
