I took tons of math and chemistry in school. Remember very little now.

I am interested in checking my own urine for simple things:
Calcium, magnesium, potassium levels, blood presence.

What simple (gotta be very simple for me to do it) tests can I do to check
these? The sort of "tests" I am looking for would be something like...

Put in one drop of some readily available chemical. Look for it to turn blue.