Its impossible to know if you're suppressed without bloodwork. I finished an 8 week cycle of LGD at 15mg a day about 2 months ago. It was also my first cycle but i learned alot, not only about my body but about anabolics. Granted im 33 and ive been working out since 16 so ive long built my newbie gains and had a solid base of muscle with a low bodyfat percentage. At the end of it i gained 15lbs and kept 10lbs, what i lost was mostly water and some fat. So lgd is good for mass but be prepared that most of that will be water and or fat.
Heres my tips...
1. EAT and Drink LOTS of water! I hope you know your maintenance macros and proper nutrition cause you can easily waste that time gaining water and fat. And keeping less than half of what you built.
2. You'll recover pretty quick so plan on working out OFTEN with LOTS OF VOLUME.
3. Sleep, as basic as it sounds LOTS of people can't get this right.
4. Consider a cycle support, but a SERM is a must. Yeah sarms arent as hars as oral steroids but they will raise your liver enzymes. For most of us its not by much, but for those lucky few it can be dangerously high. Not to mention your HDL can take a beating too. And get a serm 4 or 5 weeks of clomid or nolva either is fine. I would only consider using both if you decide to use real gear.
5. Get an AI, more specifically aromasin, durring my pct i started getting sensitive nipples. 12.5mg of aromasin every 2 days until the sensitivity was gone fixed me right up.
Im glad I waited until i was older and that I gathered info for as long as i did. Use that search function bro and good luck with your gains