I am a novice at this. After having a house built from the ground up in the most popular scenario, if there is one, what are some things a person might still have to do with the new house including with contractors.

Might there still need to cosmetic work done, or need of inspectors, if you can cover most scenarios that would really be helpful.

Any tips will be appreciated.

Thanks in advance

How involved do you want to be, and what do you want them to do.

You pick out the blue prints, give them exact room colors, pick out all the carpet, tile and the such.

Any special needs, higher counters or lower door knobs, any and everything.

How many outlets you want in every room, wired for future nees with low voltage wiring ?

Normally you sit down and decide every detail before they start,
If you want changes after they start, that is callled a "change notice" and each one costs you additional money.

If you want to hire inspectors to inspect along the way you have that right, the city building inspector will be dong the required ones.

Normally when they are done, if you agreed to it, you get handed a set of keys and move in