Seems like the place to start is to organize your thinking and your observation before organizing your action.
Observation: What's growing and living on your site, and on neighboring sites? What trees, fruits, etc. seem to be popular and grow relatively effortlessly in your area? What are the native plants in the region? A few field guides, a tour of a nearby arboretum/public garden, or even a nursery specializing in adapted plants and/or natives might be a place to start.
Try to find resources on your climate....temps, rainfall, etc.; both averages and extremes.
When a good heavy rain does come, get out in it and observe how and where water moves across the site and the neighborhood. Hardly anyone thinks of this, and the lessons to be learned are many, blatant, and worth more than all the countouring and mapping and so on!
The summary of observation is answering the questions "what does this place want to be or do? What can it do for me without a lot of effort?
Thinking: means answering the question: What are your goals for the site? What benefits can changes you make to the site provide to the
local ecosystem and beyond? A landholding, and to some extent even an indoor space, has the potential to provide at least these things, and probably others: food production,
energy provision, waste processing, water catchment,
carbon and nutrient catchment, wildlife and
native plant habitat, income generation, beauty......Decide which goals are most important and in which timeframe. This helps deal with the overwhelm that often comes with a new place. Think about which projects can fulfill more than one goal at a throw. (i.e. a looping system including the use of yard and kitchen wastes going through
chickens, worms, or
compost and ending up in some garden beds fulfills food production, waste processing, carbon and nutrient trapping, and perhaps even beauty and income generation---in the sense of money not being spent on the produce generated....)