Muscle building/ nutrition help

Nutrition is pretty straightforward for building muscle. Get about 0.7-1 gram of protein per pound of body weight per day. For you that would mean aiming to get 130 grams of protein per day. It's probably best to spread that out over a few meals, but it's a minor detail. The important thing is to get enough. After that you need some fat to keep you healthy and then you can fill in the rest of your calorie allocation with more fat and/or carbs. You want to eat enough calories such that, on average, you're not losing weight and either maintaining your current weight or gaining just a little.

Next you need to find a well structured, progressive, resistance training program. There are a lot of such programs listed in this thread:

https://community.myfitnesspal.com/en/discussion/10332083/which-lifting-program-is-the-best-for-you/p1