Don't be scared, just do your research. The fact is in a 2x4 tent you have 8 square feet and you want a min of around 35 watts per square foot. That's only 280 watts. My first plant was grown under an Amazon LED which most refer to as a blurple light. It was listed as 1200 watts and only had a power draw of 150 watts. I grew a Northern Lights Auto in the same space you have, it gave me 3.5 oz of decent bud. 2 of those lights would have given me 2 decent plants and at 3.5 oz a piece would have been fine. The reason I upgraded was the bud was not as dense at I would like. It was still nice, just not the best I could make it. I moved up to MH/HPS light and for my next grow I have an HLG 600 which arrives today. The HLG is a good upper end LED which pulls 600 watts and will produce less heat than my 1000 watt MH/HPS. Here is a pic of my first plant grown under a my blurple. To me this shows definitively you can grow a decent plant under a blurple, there are just better lights that would give better results.