I say get all you point into stamina. As an stamina nightblade you want that.

Here is some advises.
https://alcasthq.com/eso-stamina-nightblade-beginner-build-pve/
I say, you might want to get some new gear if thing goes too slow, two crafted sets say hurdling and night silence.

Get to cp 160 who is gear cap, now get new gear you will keep for some time.
And you want an second sets of weapons, most common here is dual wield.

My main is a stamblade and I run a 2-hander for solo overland questing and world boss slaying. Stampede is great for rushing through delves and Brawler gives a damage shield every-time you swing it which helps a lot to not get one-shotted when fighting world bosses alone.

In dungeons and trials, you'll almost always want to run duel wield so you can use Whirlwind for trash pack clearing. You could get away with using a 2-hander in most normal dungeons, but in a vet dungeon (especially DLC) your tank is likely to leave the group after the first trash pull if your dps is too low.

Stamblade can be a tough class to play. I've gone through growth phases of struggling to get over 20k dps on a dummy, to 27k dps, then to 33k, to where I'm now at pulling almost 80k dps. My least favorite thing about the class is that to pull high dps in endgame content, you have to be super vigilant of your rotation and have to spend most of the time staring at your bars instead of watching and enjoying the game. It also makes it more difficult to learn and do mechanics when you're hyper focused on your bars because you are competing to keep up with a range dps whose using a 2-button rotation while he watches TV.

Are you wanting to stick with Stamblade? My 9 year old son plays Magblade and regularly pulls 60%+ dps in any groups he joins and he's literally just spamming two or three buttons. Outside of dungeons he'll still go cloak and dagger while roleplaying as a thief and enjoys it just as much without being stuck in the stamina niche of skills. Magblade is arguably one of the highest PVE dps and easiest to play class in the game. You can check out https://www.esologs.com/ to see how different classes perform against each other when played by the best players.

Stamblade can still pull high DPS in PVE situations, but it takes more work. I run three different gear and skill set for dungeons and trials to maximize my dps and ensure that I'm able to keep up with the expectations of my group. The addon "dressing room" makes it a one button press to change all of your skills and gear. You just have to remember to do it and time it properly between pulls. I use a specific loadout for AOE trash pulls, single target boss, and hybrid single target / AOE situations. I'm mostly running "trifecta" groups at this point which is completing a dungeon on Veteran-Hardmode, with no deaths, and under 30 minutes and I wouldn't be able to contribute properly or even be welcome to those groups just running a single loadout as stamblade.

If you solo a lot then i suggest you get werewolf too...ww makes you very tanky and you dont even need a special build
I am nb dps with duel wield daggers and bow and i just slot ww ulti when i want to be tanky and i can solo word bosses

Just an idea...you can ask for a free ww bite then go level it to 10 by killing zombies