@ Kelly, After acquiring mutagen, if you click on the tab it tells you how much energy you need to do so. You'll need to spend lots of energy to lower the cost, but I would wait till you have to wait awhile before hatcheries or expansions are available for purchase, you want to build up that mutagen.
Maybe a tip for the block training, if it starts getting to the point where you really need to pay attention to the apples, completely ignore the stars, you will either block them or they will make it to you, but it won't matter if you get hit with an apple. Same for the strength training.
Mastermind. At a certain point with your hatcheries and expansion you start to earn mutagen, you want this to build up to a certain point, use your energy so you can ascend. Once you get mutagen it will be easy, a new tab will pop up.