looks like a cracked shingle or two there, you still have the top half of the shingle below keeping you dry, plus the felt paper underneath, but you might want to fix those. The granules wearing away is not a big deal. Don't see any curling tabs, which is a good sign. Looks like a 20 year shingle, but can't tell from here. It's not uncommon to get 25 years or better up here in the PNW.
The vent stack boot is shot and should be replaced, but you can buy some time. Slather some Henry's roofing mastic on it, wrap it with webbing, yellow self sticking drywall mesh tape will work, then slather on more Henry's.
You can get a roll of zink in the roofing dept, it helps slow the moss down. Typically it's installed before the ridge cap goes on, but you can figure something out
