Why there is no space no Ubuntu on sd card?

I got Orange Pi Plus2e, installed Ubuntu on sd card, everything works fine, but it's out of space for some reason. I did everything according to this page:

http://www.orangepi.org/Docs/SDcardinstallation.html#Ubuntu.28Linux.29

i was using ubuntu to create OS on sd card, downloaded Ubuntu Image from Google Drive

OrangePi_plus2e_ubuntu_xenial_server_linux3.4.113_v1.0.img.tar.gz

and now my root folder in ubuntu has 98% usage. But my SD card is 32 GB.

result of df -h

Filesystem      Size  Used Avail Use% Mounted on
/dev/root       1.2G  1.1G   32M  98% /
devtmpfs        880M     0  880M   0% /dev
tmpfs          1008M     0 1008M   0% /dev/shm
tmpfs          1008M   17M  991M   2% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs          1008M     0 1008M   0% /sys/fs/cgroup
/dev/mmcblk0p1   50M  4.6M   46M  10% /boot
tmpfs           202M     0  202M   0% /run/user/0

result of sudo fdisk -l

Disk /dev/mmcblk0: 29.5 GiB, 31691112448 bytes, 61896704 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x7286c418

Device         Boot  Start     End Sectors  Size Id Type
/dev/mmcblk0p1       40960  143359  102400   50M  c W95 FAT32 (LBA)
/dev/mmcblk0p2      143360 2650111 2506752  1.2G 83 Linux


Disk /dev/mmcblk1: 14.6 GiB, 15634268160 bytes, 30535680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device         Boot Start      End  Sectors  Size Id Type
/dev/mmcblk1p1       2048 30535679 30533632 14.6G 83 Linux


Disk /dev/mmcblk1boot1: 4 MiB, 4194304 bytes, 8192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mmcblk1boot0: 4 MiB, 4194304 bytes, 8192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/zram0: 251.8 MiB, 264032256 bytes, 64461 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/zram1: 251.8 MiB, 264032256 bytes, 64461 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/zram2: 251.8 MiB, 264032256 bytes, 64461 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/zram3: 251.8 MiB, 264032256 bytes, 64461 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

As you can see /dev/mmcblk0 is 29.5 GB, but /dev/mmcblk0p2 is only 1.2 GB for some reason. Is there a way to make /dev/mmcblk0p2 to be 29 GB so I can use all space in Ubuntu?

Yes, you can use gparted or resize2fs for extending your partition to the maximum available on your SD card.