Question about germinating

I want to know how long seeds are viable for. I have a friend who used to grow a lot about 4 years ago. He gave me about 50-100 seeds of each strain (skunk #1, northern lights #5, nl x big bud and big bud). I have thrown a bunch between a wet paper towel about a week and half ago and all I have seen is a couple of seeds barely cracking and a lot that have some fungus on them.

Are there any tricks to get them to germinate? What can I do to keep fungus away?

I recently put more seeds in wet paper towels and then in a plastic ziploc bag to see if it will help with the fungus.

I use paper towel for germinating; the seeds usually crack within 24 to 48 hours. I moisten a paper towel real well, fold it in quarters, and then place the seeds in the middle of the folds. Then I place the paper towel with seeds on a plate, and cover the plate with plastic wrap and place on top of the refrigerator (warmer up there).

Mold on seeds? Never seen that before, and I am guessing you are germinating for too long a time.

I let them get some air and a few more sprouted. Maybe that helped them.

That fungus may just be fuzz from the paper towels. Ive gotten that before (and ive also gotten actual mold). It doesnt seem to effect the seeds too much. Assuming they sprout, the mold isnt much of an issue once the seed is planted.

I always put the seeds in a jar of water on top of my fridge for 24 hours, if they crack then it's the paper towel in a warm dark place.