It does not appear the construction has been completed.

What are your concerns?

The eaves and valleys. Lack of drip edge. The droopy overhangs...

Really, why ask us? None of us are roofing contractors or experts on code in your unidentified state.

REACH OUT TO THE SHINGLE MANUFACTURER customer service and send them better, brighter photos. Your 20 year warranty depends on a correct installation. Make sure you are getting it.

GAF likes their installers to have a CERTIFICATION. You can check.

https://www.gaf.com/en-us/roofing-contractors/verify?distance=25

GAF Timberline

Roof shingles do not all lay down perfectly during install. Some require a bit of time and sunlite to lay down and actually seal themselves. That's the valley and the cap. Eaves, the flashings are typically done before the shingles from what i have always seen and the overhangs are not that sever typically.

I would not ask about to code as code is bare minimum for quality.

With winter upon us, I imagine your builder wanted to get the house covered. I'd quiz them about what you see.

Looks like poor quality workmanship to me. Shingles overhang too far, flashing bent up. Hopefully you don't get much snow because the waterproofing doesn't go up the wall very far.

Code does not address the issues you bring up. But the manufacturer's installation instructions covers them. You can read them to know what to look for, then have patience for construction to continue.

Fascias are not installed, so I assume the rake shingle overhangs account for that and drip edge. Same with the eave overhangs. Shingles should overhang the drip edge. Shouldn't install drip edge until fascia is up.

Flashing should be at every wall that abuts shingles. That would include step and counter flashing. The WRB should overhang the flashing. Can't tell from pics.

Valleys have multiple methods. I don't see anything out of the ordinary.

"Code does not address the issues you bring up. But the manufacturer's installation instructions covers them."

Many local codes make the manufacturer's installation instructions the rule.