I am playing this game and the king of nords didn't want to give me Reyvadin the first city i conquered,i also own a castle nearby and several villages.
Now i am called nords rebel since oath something.Can i make vassals join me or am i alone and what happens when i overtake the whole nords kingdom?
Or should i just reload another save when i am still with the nords? Which is one day ago.
All my lands are marked with grey colour.

Seems like this gives more info:
https://strategywiki.org/wiki/Mount&Blade/Rebelling

Edit:
Seems if you rebel alone you stay alone and can't get any vassals to join you,at least i don't see any dialogue options like that but you keep all the lands you get including with the tax.
But don't think it's worth it i am just gonna reload my save game

Indeed, in the original game you are making it hard in the extreme if you strike out alone. I find even taking up a throne claimant's cause is hard enough with the need to do a lot of work on improving your standing with many lords. Going alone makes for a different game where you are unlikely to win but it could be interesting to try it once; I never did, just read about it.

Okay, so I haven't played base vanilla unmodded or expanded Mount and Blade in a looooong time. I advise getting warband at least, and maybe over time try a dozen good total conversion mods(the viking conquest "game" is based on one such mod)...but back to your question.

There are two possibilities here, but I think in original mount and blade being a rebel means it is just you against the world, and you cannot recruit friendly lords or turn companions into lords. I hope it's a fun trip to Doomsville.

Other possibility: If you are not a total badass(including army) with a lot of lords as friends/in laws, you are probably going to get stomped into the ground. If you can create/recruit lords you're still probably going down, but try to get martial and upstanding lords.

~Keep in mind when trying to get awarded certain lands there are affects from things like how much land you already have compared to other lords, your renown and relation to the king, if you took that fief yourself.

Sounds like you're better off reloading an earlier save. Rebelling or starting a kingdom is already extremely hard in Warband, and requires quite a bit of preparation: you'll want to build a friendly relationship with nearby villages, since yours will be constantly raided, which means your best source of new recruits will be enemy villages, but you need to have positive rep with them. You'll also want to befriend as many lords as possible as to get them to defect and join you later, etc etc.
If recruiting lords isn't even a possibility then it's certainly not something I'd recommend a new player to do.