How do I diagnose a bad starter relay? on 1996 Nissan Pathfinder

The car will not start sometimes, but may start after several turns of the key, or after sitting for a while.

Asked by for the 1996 Nissan Pathfinder
First before describing, do you know how a really work ?
I am not a mechanic, but have worked on this vehicle .
Need to be more of an electrician than a mechanic. Search for videos on YouTube, if you know how to test one you you'll know how to test them all.
My point, good; If you start testing as some that don't know or with non-know how, you can create more problems then you have already. All I need is for you to start probing wires and short out your computer. Have someone help, that knows how to do it.