Now is a good time to stratify.

how do i stratify each specific seeds?

There are a variety of approaches but the main thing is providing a cold, wet environment for ~6 weeks before sowing. One hobbyist turns them into "seedsicles". I put them in sealed crafts bags, with purified water, in the butter keeper of the fridge.

I plant a few seeds ea. in small pots on sphagnum peatmoss/perlite with the top 1/4" pure milled sphagnum, spray them generously with distilled water, put the pots in plastic bags and stick them in the crisper for 4-8 weeks checking the moisture level and for any sprouts every few days. If they do sprout in the frige (which doesn't happen very often) I pinch the soil under the sprout with tweezers or scoop with a small measuring spoon and lift it for transplant in another pot. Make sure your new pot and medium is ready before you lift it if this happens. You could take the entire pot out but you'll probably get better germination if you leave un-sprouted seeds in the frige for at least 4 weeks.

i heard some need hot stratification?

Hot stratification (or warm stratification) is typically for Winter-growing species. Tuberous sundews from Australia are a good example of this. They experience hot, dry Summers during which they are dormant, and cool, damp Winters when they grow and their seed germinates.

In order to get their seed to germinate at home, you need to simulate these seasons with hot, dry conditions for several weeks. Then you cool things down, add some water and watch them sprout.