The first step is to get the frame ready. This is quite similar to the way you would build your home. Get the floor frame ready on a level area on your property. For this shed, cinder blocks, cements slabs and even gravel bed can be employed depending on suitability and availability.
Now the walls can be erected around this floor frame as per dimensions that you decide. Assemble the 2 x 4 s and build up the walls right up to the ceiling. However, for such a shed the space to be left over for the doors on the front side will be much larger. Procure standard plywood sheets for completing the walls. The sidings can be secured with one and half-inch screws. This part gets your basic shed frame ready.
The complex part of building a barn shed lies in getting the top correct. This particular style of eaves and trusses may require skilled efforts which can be mastered with a little patience. Using a miter saw you will have to cut out the first roof beam of the barn. Once this is done correctly you can repeat the process for all the beams. Care must be taken to cut the beams at an angle of 67.5 degrees off the 90 degree angle on both ends of the roof structure.
Get a metal brace plate that has this specific 67.5 degrees angle to attach your roof beams. Remember that the truss will form a semi octagon on the roof frame structure at this stage. The first truss must be attached to the end of the shed frame to make space for the wall below the roofing. The remaining trusses can be placed 2 feet apart along the length of the barn structure.
For additional strength, the top beam truss needs to be connected across its central angle with a cross beam. Metal brace will have to be used for extra support to the entire structure. Now you will have to attach the vertical support to this cross beam positioned at the centre of the ceiling of the barn structure. The same process can now be repeated for the remaining trusses to complete the frame of the roof.
Using 90 degree angle braces these trusses can be hanged on the top of the walls of the structure. The trusses can be connected with 2 x 4 s keeping a gap of about 2 feet along the sides.