In reply to Jacob (the J stands for climber):
Shame you can only climb once a week.
Fingerboard deadhanging with proper warm up and progressively harder hangs without going to failure is inherently safer I’d say than dynamic fingery bouldering which people seem far less vexed about. You don’t even need to let your feet leave the ground when deadhanging you can just stand on the floor and progressively load a hold with one arm or two.
There is increased risk if growing which occurs in spurts. The signs a spurt is starting to happen are such things as increased tiredness and appetite and it would be better to back off then if fingerboarding.
Other home exercises that will help with your climbing are variations on pull ups, levers and core floor exercises. A set of dumbbells are useful for complexes for conditioning and reasonably priced.
Stretching to achieve greater range of movement is another obvious home activity.
The ultimate is installing a woodie if you have the means, space and permission.
Good luck.