Welcome. Yes it can be overwhelming. Take your time and think it through, as it is definitely easier and less expensive to do things at the initial build. Some things can wait, but others are hard to do after install.
Some suggestions
1) Our shallow end is 3 1/2 feet, which is a good shallow depth for kids. Our deep end is 8', which is basically a minimum if you want safe diving.
2) I highly suggest either a 2-speed or variable speed (vs) pump. A single speed pump is expensive to operate compared to the others. A variable speed is great way to go as it can save you lots of $$ as you can dial it back to lower speeds and save electricity (I replace a 3 month old - working perfectly - single speed pump with a new VS. Wish I had found this site before my build and I would have save couple thousand $$ replacing equipment so soon.
3) Install as much decking as you can. You will be surprised how much room loungers, chairs, walking space for people, ... take up. Much easier to do at beginning and cement is one of the least expensive parts of a build.
4) Consider some built in umbrella mounts. We have a built in table with one that sits between two built in lounger (in the water) and great to have our 11' umbrella open at times so we can relax in shade while having a drink, and then open when we want sun.
5) Install a surge protector like the
Square D HEPD80 with your pool's electrical sub-panel. Its pricey to replace pool equipment. Mine protects pump, lights and salt water chlorine generator (SWG)
6) Not sure if in your area the pool will heat up much or not, but my pool gets quite warm in the summer (in NE GA) - into the 90s. I bought a couple of low cost fountains which I insert into two of my returns at night. They really work well, keeps water in 82ish range. Another reason I went to VS pump since running over night. I wish I had known this before I built and I would have built in a couple fountains instead, so I would not need to insert there every night.
7) Think about how you want to add chlorine to the pool. You can
read here for options on how to chlorinate your pool. Part of the decision will if you want to pour some chlorine in daily, get a chlorine pump, or use a Salt Water Chlorine Generator (SWG) - which is what i have.
Again, welcome!