Never heard of North Star. Looks like a great stock, good pistol grip, good rail, although its a touch long for my taste. They use a Ballistic advantage barrel, which in my opinion is a very good barrel. IMHO for whatever that is worth, looks like a good rifle.
Accessories!
trigger spring kit. Looks like this has a quality mil spec trigger, but mil spec triggers are not great. I highly recommend the JP enhanced reliability spring kit. Intended to take about 2lb off the pull weight but still have enough powder to set off hard military primers. Best part, its only $10.40.
https://www.midwayusa.com/product/1003366096?pid=698675
Vertical grip. I really like them. I tend to wrap my hand around the rail and use them as a hand stop. But you can also grab onto them, or push them up against a barracade to steady yourself. I like the magpul one. they are around $22.
https://www.midwayusa.com/product/2319353311?pid=755469
Aiming. I generally like a red dot. They are light, fast, and work well in low light condition. They are also relatively inexpesive compared to scopes and scope mounting systems. also you can still use your pop up sights during practice, or if your battery dies. Something like the sig romeo 5 is what I would choose.
Flashlight. Identifying targets in the dark is hard, flashlights let you find and identify your targets. Its really hard to shoot what you cant see. Flashlight number and ratings are confusing but basically lumens are how bright it is over all. Candella is how focused or tight the beam is, which effect how far you will be able to see. For reference, I am currently using a Olight Warrior 3x tactical. It is rated at 2500 lumens, and 78,000 candella. They state it has a 560meter range. In testing I have found it to be useable out to around 300yds,
Sling. I prefer a 2 point sling, but it can aid in aiming and stability, but more importantly in weapons retention. I hate the QD system. Really like the Magpul Paraclip system.
DONT FORGET, ammo and mags to train, and something to carry your mags with.
Heres a couple good vids to watch.
Gear history kind of the progression of gear and equipment.
Navy SEAL “Coch’s” Career in SOPMOD
https://www.youtube.com/watch?v=H6nFcledZN0&t=4s
AR-15 Furniture with Navy SEALs "Coch" and Dorr
https://www.youtube.com/watch?v=NHkVURKrnz0
Slings
"There's no right way to run a sling"
https://www.youtube.com/watch?v=xOMBZ4VORtg
Training
The Quick 60....Rifle Training on the Range
https://www.youtube.com/watch?v=A8NkLvJff2w
How to shoot faster (With Mojo)
https://www.youtube.com/watch?v=TCFRWFh4Uyc
Using a vertical grip/technique
https://www.youtube.com/watch?v=sI0KGUIDCZk
REMEMBER, this is YOUR rifle and what is important is that it works well for YOU. If my advise or anyone else does not work well for you or make sense to you, ignore it and do what works for you.