u can get a scope at radio shack if u have one near. Paid 7 bucks for mine, think it is 40x zoom and has a light built into it, if u wanted one before urs arrives
What strain are you using? Any breeder worth his salt will post up flowering times for every strain he produces. If you are using a professional strain, I'd start by looking up when the professionals chop 'em. Good luck!
Easy to tell ripe bud if you know what your looking for by eye, suppose it takes a few grows to get use to but you know and smell ripe bud when you see it.
Cannabis has been harvested for hundreds of years without microscopes. There's more to it than just looking at the color of the trichs. Learn to read your plants.
Here's an example and an excellent read. Best of luck.
https://www.rollitup.org/harvesting-curing/210501-zeuss-take-harvesting.html
8 weeks of flowering, not 12/12. Flowering begins when it begins, not when you flip the lights. They also tend to give times assuming that you prefer a clear/milky high and from their fastest phenos. If you get a slow pheno and prefer a stony couchlock you'll find their times are lowballed.its a white widow n the seed suplier sed it would take 8 weeks of 12/12 to finish well thats in 3 days