How to be more mentally active

Hey man I would say the best decision of my life was to buy a power rack, a barbell, and some weights. I would start with Starting Strength, its 3x week strength training program that if done correctly will give your body a pounding but you'll be rewarded in return. It focuses on functional movements which leads me to..

I would also buy the book "Becoming a Supple Leopard" by Kelly Starrett or just watch a lot of his videos on how the body works (WATCH THIS!Do you know what external rotation is? You should).

Here is a TL;DR on how you should perform squats and some stretching tips: http://forum.bodybuilding.com/showthread.php?t=137815533. Its helped me a bunch in being confident in my squat form. I don't even lift heavy yet (Squat 167.5 3x5) because I've been focusing in mobility but I feel great and can't wait to see how I look when I lift 225+. It takes time and discipline but it is definitely worth it. Remember that physiology is king (Mind and Body are an integral system).

Couple strength training with a healthy diet and good sleep and even throwing in meditation would be awesome to learn how to enjoy the process of becoming a better person. Good luck on this journey if you are serious about it because it isn't easy but might as well strive to be your ideal self.