Deadlands Classic or Deadlands Reloaded (Savage Worlds)?
In Reloaded, important NPCs (and PCs) usually just use tokens to represent health. Unimportant NPCs are usually either fine, Shaken, or out of the game (Up, Down, Off the table). Tracking health isn't really that hard in SW tbh.
For abilities I normally just make notes with a 'stat block' to refer to for combat. I have tent cards for the PCs so I can see their combat stats at a glance (rather than keep asking), and on the back are reminders for the players. Once you've played a few times you'll probably remember them anyway.
Storytelling-wise, for descriptions try to paint a picture using a few different sentences and senses. I normally go 3x3, normally sight, sound, and another (smell, touch etc.), start big and finish on a small detail to add 'realism'. Don't assume that more is better, it's subjective but you're probably better off leaving space for their imagination to fill in; just the right amount and no more. Decide what tone you want and speak with that in mind. Deadlands is good in this respect because there should always be something weird you can point out and juxtapose with the normal western stuff.
Have a look through TV Tropes and use or avoid those as desired. Familiarity can help draw people in, overuse can drive them away. It's always useful to make yourself aware of the genre tropes in a game, some people like to see and use them, others don't.