I don't know how activity will increase
do i must post first to make activity increase from 30 and then will increase to 126?
Those accounts' activities increase just by posting. For example , for first account you post 90 posts in 1 day(week). Then your activity will increase directly to 120+. It will be equal your post number until your total posts reach 126. If your total posts are higher than 126 , your activity stucks at 126 and you have to wait 23th (or 24) of June for next activity increase.