Looking at the pictures I see that it looks like about 1/3 of the garage is below grade on 3 sides. Also, it appears to be a new poured concrete floor.
Firstly, concrete block and poured concrete are very porous and are not in the least moisture resistant.
The idea solution would be to dig down on the outside of the foundation and waterproof but, I think is rather draconian for what you require.
Because the floor is slab-on-grade I would not worry too much about it. Any water will run away from the front of the garage unless the floor slopes to the back which it does not appear to do.
If it were my garage I would first seal the concrete block walls with some sort of masonry paint (dont' worry about the brick which is above grade).
Install some sort of roof vent or even just crack open one of the windows. Just get the air flowing somehow and I think you will be fine.
Keep checking the humidity levels inside the garage and see how you are doing.
There are other more drastic steps to take but, start with the basics.
Peter
