First time popping regular seeds...so how soon wil...

switching to 12/12 light cycle about week after should be showing if males and females after. Also males tend to be little taller than bushier females in veg. Yep had mutant leafs sometimes they go away but sometimes occur somewhat random places. But don't worry about those.

I've never had a mutant like that before but I've seen other people have em. Sometimes it stays that way the whole grow and other times it goes away after a few nodes. It is interesting, to say the least. As far as sexing goes there are a few ways to do so. number one and the easiest but least convenient is to just flower the plants when you normally planned to slower them and then get rid of males as they show up. This takes more time and if you wind up with a bunch of males can be a waste. Option 2 is to take clones around week 2 or so and root em(takes about a week). You should be able to do 12/12 from the start of the cloning and find out the sex in a couple weeks. This requires more space and another area with no light leaks, but saves time and lowers the risk of pollination vs if you used method 1 and didn't catch a male fast enough. Option 3 is to veg the plant long enough for it to reach maturity and show preflowers. They are kind of hard to see but if you use a magnifying glass or a cheap phone camera macro lens its easy. This method takes the longest and is the least reliable but is the safest to not have any pollination happen.