You First order of business is to build a basic four wall structure with a sound roof. You have 3 walls the rest is trash based on your previously posted video. Tear down the tin wall and build a solid wall with a hefty door, doesn't have to be brick.
Then tear off the flat tin roof and replace with a code compliant roof for your region. This might involve adding roof trusses adding pitch to the roof, then sheathing, roofing felt and shingles.