Couple things to consider.
Is it adjacent to house?
You will need to insure a slight grade to drain water away.
The degree of freeze thaw will determine how deep a base pad you will likely need.
You are looking at probably an 8-10" depth from desired surface level. Lime scaling for the below grade, tamper (hand or motorized rental type), and polymerized sand for the finishing of anything with individual bricks, pavers, uniform stone slabs (infill). There's likely some good DIY videos on youtube.
Other options:
Stamped concrete: there is lot of variety to this and can get most any effect of other types of surfaces.
Modular decking - easy to do yourself not as much character. (UDECX is one manufacturer)
An analogous comment
Can't decide.....Pavers or poured concrete patio?