I’ve successfully germinated seeds I kept in a film canister in a drawer in the bedroom for almost a year.
Now, about different strains. Two types of effects. One is a mellow, relaxing, let’s not get off the couch feeling. That’s indica. The other is an energetic, let’s get moving feeling. That’s Sativa.
Now they some differences in growing also. Indica dominant strains are more likely to be short and bushy. Sativa dominant strains are more likely to be tall and lanky.
There’s also a big variation in flowering time for different strains.
If I were only to grow two plants, I would have one of each. I would start the shorter plant three or four weeks before the taller plant. I would start them flowering at the same time.