Cotton has a 2013 MacBook Pro, and recently had to buy a battery from MacSales.com because it began to swell. He also replaced the SSD. He had to remove the battery with acetone because it was glued in. But after installing it, the laptop was dead. Leo says to head over to iFixIt.com and check out their instructions on replacing the battery in his laptop. He may have missed a step. But it's also very possible that Cotton may have shorted out something like a fuse. At this point, there's only one place he can take it... the Apple Store. And it may not be worth repairing.
There is one thing he can try: he can take the battery out, and then plug in the AC adapter and see if it boots up. If it does, then it's not shorted out. That means there's a loose connection somewhere in the battery installation.
Cotton also got an email saying that a hacker got his password and breached his email. Leo says it's a scam. He can ignore it. But if he wants to see if his email has been compromised, he should first change his password and then go to haveIbeenpwned.com and see.