I am new to this game, and have a few questions. Are battles random or placed? Is there much grinding in the game? Is there a way to see what my character can interact with from far away, or can I only find that out by getting close to an object or person? How fast do enemies respawn? Anything else a new player should know?

. Are battles random or placed?
Both, they are random when you move in their area

. Is there much grinding in the game?
Not much, but there is some if you want to actually do all the stuff, but you don't have if you want to just finish the main quest

. Is there a way to see what my character can interact with from far away, or can I only find that out by getting close to an object or person?
Only quest givers NPC are seen, others spawn (so it can be a problem, some may need spoil to finish a quest).

. How fast do enemies respawn?
Not fast, but there is a drink to make them appear faster

. Anything else a new player should know?
It does not very feel like a vampire game: I think vampire is here as a mechanic feature of the character, I think the story was made on this, and not the reverse.
So you can play even you don't like vampires.