I started just like you... and I'm taller.
At this stage of the game, since you are a beginner, you're gonna gain mass even if you don't do everything right. But why slow yourself down when you can go faster?
To make things simple to you, this is my simple advice before you drown in 1000 replies with 1000 suggestions.
1. Hire a personal trainer to (a) create a training routine to you (b) show you how you should execute each exercise. If he just creates your routine and shows you the exercises just ONCE every 2 or 3 months is good enough for now. If you can afford, hire him to help you once a week or more, but once every 2 or 3 months is the bare minimum.
2. Hire a sports dietitian to (a) create your diet and (b) measure your body fat percentage. You have to go back at least once every 3 months; once a month is ideal. This will allow you to maximize your gains without adding a lot of fat and you will be able to track how much LEAN mass you're putting on instead of relying on the mirror or just counting your overall weight.
Advice from a fellow tall ecto guy: the mirror is NOT your friend. You will NOT see results "in 3 months" as the shorties do. It takes a lot longer and if you really want to "feel" the progress, you will need these body fat measurements to tell you how much lean mass you're putting on.