I cannot sign up, only find login in Eduma and Learnpress.

YOu have to 24 hours support like Bluehost, your support is not convenient at all.
You have promised 6month support after purchase of Eduma theme.

I bought and imported Demo One instructor and main Demo well already.
I cannot sign up, i find only login.
Which part of customization needed? where can I find to change it.

Try to contact the author via item comments section:

Try to get in touch with your author. If support is not expired then author is obliged to offer you complete support and service