hi and welcome to SS.
in the arid SW i think water supply is the most critical thing for gardening and determines a lot of what you need to accomplish and plan for. so that is the main issue which drives the rest.
look into permaculture for arid climates. it has a lot of very useful techniques and ideas.
on new land the most important thing is to observe as much as you can. for arid climate you want to consider wind breaks, shading and how to capture and hold whatever rains you do manage to get while at the same time also not saturating potentially unstable slopes/areas.