I like where you're going with the Naga, more or less, Vince, but the heritages are meant to be a bit on the barebones side so the Culture can carry a lot of weight on it's own. I'm also definitely not going to proscribe alignments for this one.
Naga
Age: Naga age similarly to humans, but their aging slows dramatically once they reach adulthood. They're known to reach 160 years at the extreme, though most perish between 140 and 150 if accident or malice do not take them sooner.
Size: Naga are between 8 and 10 feet in length, though the vast majority are 9 feet long. Their slender but muscular bodies keep them fairly light, comparatively, and they typically weigh only around 400lbs. Your size is Medium.
Speed: Naga slither at 40ft per round. However they are incapable of making a standing high jump. Instead, they may extend their upper body up to a height of 7ft, allowing them to reach upward much more effectively than most peoples.
Poison Resistance: Naga are quite resilient against poisons of most kinds and take half damage from any poison they are exposed to.
Serpent Strike: Naga can take the Dash action as a Bonus action.
And then the rest of their traits, languages, skills, kits, etc, are determined by the culture they're from.