How can I format unallocated space on mmclk0?

First of all, I want to thank you for the time you spend with this help.

---- What I am trying to achieve? and Why?
I intend to learn how to work with this electronic board. I want to be comfortable with the manipulation of burned out various ROMs, advantages and disadvantages of each, and so on.
Partitioning management is part of this learning.

My problem with the partitions, started because I read here in the forum that this was possible with Gparted and now I know that this is not possible

Now back to the subject I can see how partitions are.

root@Khadas:~df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.3G 0 1.3G 0% /dev
tmpfs 300M 32M 269M 11% /run
/dev/linux 58G 2.9G 55G 6% /
tmpfs 1.5G 51M 1.5G 4% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.5G 0 1.5G 0% /sys/fs/cgroup
tmpfs 1.5G 20K 1.5G 1% /tmp
/dev/multiboot 32M 30M 2.8M 92% /boot
tmpfs 300M 20K 300M 1% /run/user/1000

This is different from your partitions but it’s okay. There is no memory loss.
Thanks for your help.
Have a nice day.
Aaabento