I recently started a playthrough of morrowind with a Knight type character, I don't really know what to do but What guilds/factions would suit characters like this.

The default Knight class?
That would fit perfectly with the Imperial Legion, House Redoran, and the Fighters Guild.

If you made your own custom class, then I have no idea what skills you picked. But any class relying on melee combat that favors Strength and Endurance will also find those three factions a good fit.

It is basically the crusader knight class that I included with this just look at the screenshot http://download.fliggerty.com/download--1118