There is no magic pill in gaining mass, unless you want to go the steroid route.
If you have fast metabolism, you starter pack should consist of- whey protein, mass gainer (high carbs) and creatine.
Will be taking whey protein after your workout and first thing in the morning, as those are the times when you need to feed your body as fast as possible to avoid it going into catabolic state.
All other times mass gainer should be taken in between your meals. The time to take creatine doesnt really matter.
The brands to take will purely depend on your budget. Local brands would recommend Evox and SSN, stay away from USN and Biogen.
Dont forget that no supplements can substitute a proper diet!
Source: Gyming for several years, fitness model