Hi Opti,
It’s good that you are thinking about this. It will keep you safe!
I’ve done lots of resin work in a garage. It works very well in the respect that it allows for a lot of air ventilation since you can raise a door to get more fresh air in.
Where things will get tricky is trying to keep it climate controlled. While you can do resin in warmer weather, the problem is that the pot life of your resin will be shortened. You may not get everything done before it starts to cure.
As for explosions, as long as you aren’t working with large amounts of flammable items, you should be fine. Resin in of itself generally isn’t flammable (check the SDS of the specific one you are working with) unless you add something like acetone or alcohol to it. I do however, always have a fire extinguisher close by in case something happens.
Does that help?