@OP
I hate to break it to you, but becoming a GM is not feasible considering your age and rating. You can’t become a GM through online 30 sec. Also, while I understand that beating your Dad (1200) is a nice personal accomplishment, in the wider chess world beating a 1200 is not an accomplishment. I’m about your age (14) and rated like 2100 (OTB) and my chances of becoming a GM are very slim. You can still enjoy chess but you can’t expect to be a GM.
I have 30 minutes - 10 min?
sure that works