Just Bento

If you click on the phrase "dashi stock" in the sushi rice recipe it goes to this page that explains dashi stock in a lot of detail. Dashi is Japanese soup stock, and is a fundamental building block of Japanese cooking. You can use instant dashi stock granules if you'd rather not bother making it from scratch. You can find dashi granules at Japanese or Korean grocery stores, or nowadays even at Whole Foods. A popular brand name is Hondashi - here it is on Amazon.

If you want to make sushi rice in a hurry though (you must start with properly cooked rice though - overcooked rice will end up a pasty mess, undercooked rice won't stick together properly) you can get something called "Sushinoko", which is a powder that you can just mix into freshly cooked hot rice to turn it into sushi rice. It tends to be rather salty though and has MSG, but as I said, it's a shortcut. Sushi no ko is sold at any Japanese or Korean grocery store or online from Amazon.com.

No you don't need wasabi if you don't like it. It's like tomato ketchup on a hamburger - traditional but not necessary.

Maki has instructions for cooking sushi rice at http://www.justhungry.com/2003/11/japanese_basics_1.html
There are lots of different sorts of sushi, but assuming you want to make rolls there are instructions for doing so without a sushi rolling mat at http://justbento.com/handbook/recipe-collection-mains/sushi-roll-bento-m..., and if you HAVE a mat you just use the mat instead of the tea towel. The easiest sushi to make is a bowl (or bento box) packed with sushi rice and topped with whatever you like. Like http://justbento.com/bento-no-20-shrimp-chirashizushi-easy-sushi-bento

I saw the recipe but it calls for dashi. Not sure what that even is lol.

Also, if you don't mind using MSG, you can use a little bit of that or even Accent seasoning (which is basically MSG) instead of the dashi - just put a pinch into the cooking water, or mix a pinch into the hot rice.