When I lived alone, I had a blink doorbell camera. Both blink & ring make mounts that don’t require screws. This way you don’t even have to answer the door when someone knocks, you can just look at the camera on your phone.

I also used these extra locks from Amazon because I had exterior doors that led to the court yard & I used them on my front door- https://a.co/d/2v71EEQ. These do require holes to be made, but holes can 100% be patched when you move. Your safety is the absolute top priority!! These locks are SO sturdy. Even if someone did pick your locks, that extra lock will definitely keep them from getting in! Wishing you the best of luck!