Hey TimisStrange!
There are a few things I recommend doing. Firstly if your friend does want to give you perms, the overall command is /p perms. But this friend can set the perms for different party member roles or even enemies, allies and neutral parties. I would suggest firstly, allying his/her party by doing /p ally (party name). From their he can set what perms he/she wants for allies only.
You can also get access to perms in his/ her party by joining it. From their he/she can set what a normal member, mod and co-leader can do in the party.
The party perms allow players to do things such as breaking blocks, building around claimed area, opening chests, banning or kicking a player out of a given party, etc.
Hopefully this answered your question but if not, you can talk to me on the forums or on discord.
Stay groovy,
Katie