Where do I start?

Start your weight loss journey setting up your MFP goals and then start by accurately measuring your food and make sure your calories eaten are less then the calories burnt. Excercise is good for you, but weight loss happens in the kitchen

Don't stress yourself out trying to be "perfect". Focus on a calorie deficit, whether by diet, exercise, or a combination. Everything else is secondary (or tertiary).

When I started MFP, I focused on three things:

1. Eat within the calories MFP set me.
2. Walk at least 25 minutes daily, even if it was just a few circuits around the block. And if the weather didn't permit, I've got a fitness glider in my basement. It's not the best fitness machine out there, but it's better than nothing.
3. Restrict homemade desserts to 200 calories or fewer per serving.

Over time, as I got used to what I was doing, I started focusing on hitting my protein target and discovered that I felt less hungry when I did. At a physical, my iron levels showed borderline low, so I switched out sugar for iron on the diary page and worked on hitting that too. After a few months hanging out in the forums and seeing so many posts about the importance of preserving muscle, I incorporated strength training. My walks got longer. (These days, I shoot for 2 hours a day). I switched from measuring cups and spoons to a food scale for better logging accuracy. But it didn't happen overnight.

Make small changes you can live with. These may not necessarily be the same changes I made. Over time, you'll discover you can live with more.

Good luck!