What kinda phone is it? Maybe we can guide you that way too.
You will want some way to water them if you are gone for two weeks.
Auto timelines generally go like this (please understand this is a generalization not an exact timeline)
1 week seedling phase
2-4 week vegging phase
7-10 days transition (preflower)
8-10 weeks flower
When you bought the seed, a “flowering time” was listed, go back to that listing and apply it to the timeline. This should give you a ruff estimate of when they will be done.
There are lots of ways to water plants automatically various devices and timers. Best way is to have them watered by someone you trust, don’t pick that 1 friend who is loyal, but dumb like a stump (everybody knows one of these) while you are away.
You will not want to give it nutes unless it is in the phase you are trying to feed. You MUST read more about growing your plants. I can tell by your woes that you have much you need to read.