7 put one side of tire onto wheel
8 put in tube slightly inflated to shape.
9 put other side of tire on
10 make sure it fits correctly
11 pump tire .. throw cap in garbage if using presta.

also check your tire by running your hand along the inside of it... if you feel something sharp or start bleeding remove whatever is stuck into the tire

and yes your stupid for riding the rim..

make sure your rim tape is covering all the spokes as well.

for your shifting retension your cables at the derailleur...

use the search function ..