Attaching walls to the floor.

I have searched all over this site but am still quite confused...
I got an old pop up camper. Roughly 6x9, which will make a pretty great sized camper. I plan on making a Benroy or a variation of it. I will put 2x2 wood framing over the metal frame with marine grade ply wood over that. Insulation will go in between all the 2x2s. (Also not quite sure what kind of 2x2 wood or bolts I should use for this and connecting to the frame.)
My question is, what is the best (structurally) way to attach the walls to the floor? Should I just bolt the side walls to the 2x2s that are also bolted to the frame?(Also, what type of bolts or screws?) I feel like over time the movement of the trailer and weight of the entire top would wear down quite a bit.
I am very new to this and very new to building in general... I appreciate any advice I will get here.
I got an old pop up camper. Roughly 6x9, which will make a pretty great sized camper. I plan on making a Benroy or a variation of it. I will put 2x2 wood framing over the metal frame with marine grade ply wood over that. Insulation will go in between all the 2x2s. (Also not quite sure what kind of 2x2 wood or bolts I should use for this and connecting to the frame.)
My question is, what is the best (structurally) way to attach the walls to the floor? Should I just bolt the side walls to the 2x2s that are also bolted to the frame?(Also, what type of bolts or screws?) I feel like over time the movement of the trailer and weight of the entire top would wear down quite a bit.
I am very new to this and very new to building in general... I appreciate any advice I will get here.