What does Bulk Aging mean

is this different than letting it mellow in a secondary for a while?

Bottle = NOT BULK
Carboy, Pail, Keg = BULK

so when people are saying that they go from primary to secondary and then to bulk age, its 2 rackings and then more sitting?

You can bulk age in secondary. But if you can, no reason not to rack to tertiary for clearing and aging.

Food for thought, you can bottle age too after the cider has cleared in secondary. I usually do this to free up my Carboy.

should i filter this at all, maybe through a coffee filter or something?

No, don't filter in a coffee filter. Just let it clear by sitting in secondary or tertiary for a month or two. Some people use filtration systems before bottling, but it can be expensive and I would say it is unnecessary at your level. I say that because I too am pretty new and consider it unnecessary for myself at this point, especially since I see very few people using filtration systems at all.

Given enough time, everything I have ever brewed has cleared. That could be months post bottle, but it is inevitable unless you are brewing beer and get a chill haze, which I don't believe those proteins will ever settle out (not sure). The part that I think some people have differing views on is how much yeast should be dropped out pre-bottle. The color should be a light yellow, not the murky brown. After that, it is a matter of yeast flocculation.

It all depends on what you are shooting for and in the case of Cider you want it clear imho. (although I'd imagine some folks using a Hefe yeast strain might be interested in a cloudy cider). It can be aged, but I am not terribly certain how much better it gets over time. I have a few bottles left from last year that I might keep around to see, but it seemed that once it hit around 6 to 8 months it really didn't change all that much but then again, I am not sure if it goes longer if it hits another level of complexity. I have plenty of cider this year, so in 5 years maybe I can answer that .