I’m new

Welcome, Marcus! Your statement "gain weight to turn into muscle" is a bit off; your goal is to gain muscle. Fat doesn't "turn into" muscle, nor does muscle turn into fat for athletes who stop exercising.

Your approach should be three-fold:

1. Add 250 calories per day above whatever keeps your weight constant
2. Keep protein intake high: start with about 0.8g per pound of bodyweight (1.7/kg)...can always adjust up or down later, but this is a decent starting point
3. Choose a strength-training program which hits all parts of the body (no skipping leg day!) and can systematically progress (or get tougher as you get stronger).

The final part of the puzzle is patience. Building muscle takes time, months and years. Do it faster, you gain fat along with the muscle. It takes time, but the results are so worth it!