My essentials are: sea salt on hand (my container of sea salt sits on a shelf rather than in a cupboard) and chalk.
Chalk’s super handy because you can draw on just about any surface with whatever symbols you find protective (or just write some words you find a source of protection or strength in)
Salt’s useful to pour over doorways/windows/other thresholds to protect. I know one witch in Hawai’i that had a little mound of sea salt on their front step. Swore up and down that it protected them from their abusive father’s ghost.
The best protection spells are the simplest ones I find. Growing protective herbs or plants at the door. Wash the floor with water that’s you’ve laced with protective energy or herbs/crystals/etc.
Iron is super useful. I got two huge iron nails at Lowe’s for .97 each. I doused them with protective oils (a really, really foul smelling oil I made up) and stuck them out in the yard on either side of the door. I know someone who keeps a pair of scissors in the window to ward of fae. (I keep a pair of scissors under the bed for the same reason).
A witch-bottle is super useful and doesn’t need to be complicated. Some broken glass, nails, and whatever other nasty things you can thing of go inside a jar you don’t want (spaghetti sauce jars are perfect for this). Cap the bottle, cover it in wax, and bury it in the yard (or if you don’t have a yard, a flower pot).
Charm bags are super easy to make and only require something to fill a charm bag. For an emergency, you can use a cupcake wrapper tied into a ball, a piece of paper or paper towel folded like a triangle. Many protection herbs are found in the kitchen or can be taken out of neighbor’s yards or parks it’s you’re truly desperate.
I also keep an object by the door that I touch each day as I leave the house. I started this by saying, “I will have a good day. I will be protected.” And now it’s become habit to not even bother saying the little words but just touching it. I did the same thing for my mother but I made it her key holder rack by the door.
As for what to do with the spirit… If you’re comfortable with divination you can try that. Or you can do what my brother and I do: we just tell the spirit flat-out: “here’s the rules” and then lists what is and isn’t acceptable, just like you would a new room or housemate. We aren’t hostile about it, just matter of fact.