Where is a good place to start for people with no experience? Are there apps to help with meal planning for different situations like height, weight, activity level and specific goals, or do most of you just figure it out yourselves?
Weekly meal planner is a good app.
I recommend doing 4 things in addition to the app considering 3 meals a day: your budget, what to buy, what can be done with what you bought and how to store what you make.
for example cheaper cuts of meat can be a little tough so they are good for stews, hamburgers and meatballs all can be frozen and the last two still raw depending on the additional ingredients including seasonings can be quite nutritious.
the same with beans and lentils (soy is an exception it is difficult to prepare the beans because they taste terrible) you can make soups, stews, salads and pattys or even sauces (like hummus) and purees (pea puree) all are cheap options and easy to store while raw and can be frozen.