I have a red Kayak Pungo 100. (30" x 10 ft) It is 30 inches wide because it almost never flip over. The narrow ones really flip over a lot especially novices. I bought it at Dick's Sporting Goods store.
If you are a novice, then you really practice it on a small brook or a big pond with your friends often. Then, you will feel ready to go on a big river. It is too dangerous for you jump in without experience on it. I don't care what other people say that it's not a big deal.
Do you have a life vest (PFD) for kayaking? A life vest needs to meet for kayaking only. Most vests are for boating and canoes. See the link:
Kayaking PFDs - Kayak Online
To meet the right vest for you (for example):
Touring Life Jackets & Touring PFD's and
Helmets and Personal Flotation from REI.com | 100% Satisfaction Guarantee | Customer Reviews
Here is a list of Kayaking paddings:
Kayaks Paddles from REI.com | 100% Satisfaction Guarantee | Customer Reviews
I have Seven2 paddles (brand) -
Iso Touring Paddle It is a thin frame and easy to use. It is just my preference. I think that you would like it.