you have to remember everything is person dependant and come with various side effects.
if youve never done a cycle dont go for the strong stuff. you need to know how your body responds.
Halodrol
Epi
Tren Xtreme
Bold 200
furazabol
prostanozol
are all good first choices with a very easy PCT and dosing schedual, you figured out what you want to do which is gain mass, you now need to figure out which one to use, the furazadrol can be stacked with halo for a girst timer because they are both mild, but you shoulde really run compounds alone to see how you react.
i personally think you should go with Hdrol by CEL and run it 5-6 weeks, itll give u a bunch of workouts while on and a good amount of lean body mass