Do not caulk between siding and any built in receiving channels located at or around windows.
Seal gap between siding concrete.
Not a vapor barrier as you say but it prevents water that makes it past the siding from getting any further into the wall.
I believe you have tar paper under your siding based on your description.
How to seal and fix a gap between foundation and concrete sidewalk or patio.
To prevent further water damage install closed cell backer rod in the gap between the patio and house foundation and cover it with concrete crack sealant.
Find the entrances mice use to enter your home.
Use a small.
Theoretically you could seal the tar paper to the foundation with foam spray caulking something similar.
Vertical trim gap caulking.
How to seal siding to keep out mice.
Since some of the siding looks like it will need re priming and painting make sure that you use a paintable type of caulk.
Note that there are various types of caulk.
Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement.
In this case what i would use is a polyurethane caulk made for masonry like this one.
The urethane caulk sealants were developed for the joints between the panels in concrete tilt up construction.
Loctite pl10 often the gap to be filled is quite deep.
Crawl around the exterior of your home and use a flashlight to find cracks holes and gaps.
In that case the use of backer rod before caulking is recommended.
I am going to assume that you have a concrete patio which has a small gap where it meets the house foundation.
They are typically mechanically robust adhere extremely well to almost everything especially wood and concrete and are stretchy enough for seasonal building movement.
Always caulk between the siding and the trim.