I just now noticed your post. Welcome!
You are in the same vicinity as where I used to live when I was in high school. Now, I live in Wimberley but drive in to Austin almost every weekend to shop at Central Market. I love that place but have narrowed my shopping list down to 2 lbs of salmon every week to grill and put in my lunches for work. MMMMMM. I also pack almonds from CM. I do buy some veggies there but also use my local grocery store.
As to losing weight, it's fairly simple conceptually... you have to burn more calories than you consume. Personally, I don't count calories regularly but I do check in at
FitDay occasionally just to keep a rough guess of my intake based on what I normally eat. You might want to check it out to at least give you a feel for it. Johnka is the expert in this category and has it down to a science... and it shows!
As to the burning calories part, you will probably find that there are some folks here who like to do only resistance training (weights) and others who prefer the "aerobic" of "cardio" style training. Most will use some combination of the two. As johnka said, look through the training section and ask questions... there's a lot of great advice from some really knowledgable folks there.
Best of luck on your new endeavor and look forward to hearing of your progress!