Follow these 5 steps to use the texture packs that you have downloaded.
The first step is to download the texture pack that you would like. The downloaded file should have .mcpack at the end.
Make sure you have minecraft bedrock editon open on your pc. Double click the .mcpack you just downloaded. It should open in minecraft. Let it download.
Once it has downloaded, click settings. Once in settings scroll down on the left side to "Global Resources". Click on that, and then click "My Packs" Find the pack you have just downloaded, and press activate. Wait for it to activate, and then click "Active" to double check that it is working.
Join a world, and then find the item the texture pack should have effected. Congrats! You have successfully added a texture pack to bedrock!
You have successfully added a texture pack! Enjoy!