My plans can be modified but you will have to do a little thinking.
You will need to add a sandwiched 2x6 header in the same line as the top plates on either side to rest the trusses on. Attach these to the front wall of the shed. Add uprights at each corner to sit them on. Then you will have to use a covered truss at the front shed wall and another one at the front of the porch.
This will make the shed its self 10x12, the porch 10x6, and the overall roof size 10x18.
You will have to use the deluxe gable plans (or the tall barn plans) as the trusses of the regular gable plans sit on a slanted top plate.
You will need to add a sandwiched 2x6 header in the same line as the top plates on either side to rest the trusses on. Attach these to the front wall of the shed. Add uprights at each corner to sit them on. Then you will have to use a covered truss at the front shed wall and another one at the front of the porch.
This will make the shed its self 10x12, the porch 10x6, and the overall roof size 10x18.
You will have to use the deluxe gable plans (or the tall barn plans) as the trusses of the regular gable plans sit on a slanted top plate.