Can't build, mine blocks or open inventory

So, I join my Minecraft world. I decide to build something. I press E to open my inventory, but it doesn't work. I have a touchscreen computer, so I have to press on the screen and tap on the three dots that appear beside the inventory with my finger.

After using my finger to get a block, I right click to place it. It doesn't work. Again, I have to use my finger. I also have to use my finger to open doors.

After using my finger to PLACE a block, I try mining it using left click. Again, no reply. Punching villagers, mobs etc. doesn't work as well.
PLEASE FIX THIS! I LOVE MINECRAFT BUT I CAN'T PLAY BECAUSE OF THIS!
P.S Roblox is not as good as Minecraft, but I play it anyway to spend my time.