The following are a couple simple wood plans for chairs that you might call “Deck Chairs”, “Patio Chairs”, or “Garden Chairs.
The first is from Lowe’s. The picture is linked to the free woodworking plan. You can print the plan and bring it into a Lowe’s store. You should be able to leave with all material needed (lumber and hardware).
This second version is a nice plan from the folks at Buildeazy.com.
Simple garden chair plans
The final version is a nice design that I favor:
Good luck with your woodworking projects. Summer is here!