Replying to Build a drop in with almost nothing ?

alright im looking to build a drop in for my backyard this winter and dont have a whole lot of materials

i have:

a four foot saw horse

6 foot board walk

a bunch of plywood

and some 2x4s

do you guys think ill be able to do much with all that or do i need to go buy some more shit. already have rails and boxes just need the drop in