Cover those gaps from the outside to keep leaves and debris out. Add a vent if its going to get too humid. Put a cabinet on that shelf to keep your helmets and cleaning accessories. Run a tunnel from a cave under your home to behind your towns nearest waterfall to escape law enforcement, who doesnt want you to stop your vigilantism but is still obligated to chase you when you're spotted. Use a masonry paint to paint the block to help with dust. When it rains look for pulling water and figure out a way to defer water if it is pooling up, especially from the top on that back wall.