How to install textures in Minecraft Bedrock
Texture packs usually come as .mcpack files and are added to Resource Packs.
Download the pack
Save the .mcpack file. Do not extract it unless the creator specifically tells you to.
Import it
Open the file with Minecraft and wait for the import to complete.
Enable the textures
Activate the pack in a world’s settings or under Global Resources.
Pack order
When using several resource packs, move the desired pack above the others in the active packs list.