AW16...You start threads about screws, COBs, heatsinks, sandpaper, mounting, connecting, etc., etc. etc. when every one of your questions was answered in Growmau5's six seminal Youtubes and again in multiple existing threads in this forum.
You seem like a good kid. I'm not trying to slam you. But dear lord you have to learn to conduct some research on your own and develop the initiative to make a move without seeking prior approval. This is a life skill that will serve you well. Master it.
Get a volt-ohm meter. You've spent hundreds on COBs--spend $20 on a VOM. You need one, if only to ensure you don't kill yourself with a short. Research a good, inexpensive one on the 'net. Check Amazon reviews. I know for a fact that folks have recommended good ones here on RIU. Either learn how to use it from the many excellent YouTubes out there or go to the library and pick up a book.
You need to know the difference between serial and parallel connections. Again, there are many fine tutorials on the 'net. You're a smart guy, you can master this stuff.
Watch all of the Growmau5 videos. Now watch them again. He explains serial connections. That's what you want.
Good luck.