Ingredients question

i`ve been looking at some beer recipes and they call for things like 2 row,polyclar,irish moss,Dextrine,Crystal 40.i`m new to brewing os i`m just starting i`ve already brewed a dry extract kit but all it had in kit was bag of dry extract, hops pellets, and a bag bottling sugar

Just do some more reading. Everything you sited in that list are common ingredients. I recommend if you haven't already, get a book or two on homebrewing.
"The Complete Joy of Homebrewing" - Charlie Papazian
"The Brewmaster's Bible"
These two are excellent!!!

Or

"Homebrewing for Dummies"
This one got me started. I know it seems really cheesy, but I did what I had to do. I love this stuff. I don't know near as much as some of the guys here, but I read more each day. I strongly recommend you do the same. Your hobby will turn into a passion.

That's a huge question. 2-row is simply a form of malted barley used to to get fermentable sugars, not something you would use unless doing all-grain or partial mash brewing. You might use crstal malt, which impacts some sweetness and body (and is used by extract brewers). Irish moss and polycar are used for clarity.

What you should do is spend some time at www.howtobrew.com to get familiar with the whole process and what the ingredients are. It's a great site to get familiar with all the basics of homebrewing.

Malt, water, hops, yeast. That's it.

You have dry malt extract, but all that is is sugar extracted from grain and dehydrated. Once you've done a few batches, you'll want to look into steeping specialty grains to add more flavors to the extract. Then you are on the slippery slope into the dark hole of all grain, yeast farming, hop growing ...