Change ownership of new partition topic

I just created 2 new ext4 partitions using gparted on my primary hard drive. System is running Lubuntu current version. Cannot write to partitions.

I have seen many threads on this topic, and cannot get any of the solutions to work yet.

I hate having to do such tasks in terminal - is there any other way? Is there a way to recreate the partitions with correct ownership as workaround?

If neither, please help with correct terminal commands. Please, step by step and very complete and simple as possible - terminal is new to me.

Thanks!