When I was 15 I was working a minimum wage job . I actually liked it

For next time, post pictures or explain it to us online and we will tell you how to do it(if we can)

I had the same issue as you not too long ago, and the chain was tangled(I put the frame ni the backseat and wheels in the back and started to reassemble the bike at the LBS). Took me 15-20 minutes but I got it back on, I am very noob as well about the whole thing but the effort and strong will to make it work is what helps me in life. Work a few jobs where your required to make the round peg go into the square hole a couple of times and you will be good at DIY solutions.