Any portable decks out of pallets ?
Pallet material varies so much that it can’t be used for load bearing building materials, as far as the National Building Codes are concerned (the IRC, in the US).
You’ll find plenty of stationary pallet posts here, but making them portable adds two kinds of kinetic loads to the structure.
If you don’t want to hire a pro, the I recommend that you look up what’s called the Type V Prescriptive Methods, where you’ll find Span Tables, fastener schedules & more.
I agree with Cheryl. Pallet material is not suitable for decking. If you are looking for economical options, check out your local building supply salvage yard.