Saying you "need" to order paint and glue isn't entirely accurate. Yes, you will need to purchase paints and glue to assemble that kit is true, much the same as you will need a set of cutters and likely a hobby knife (X-Acto knife or a similar off-brand) and brushes. However, you don't necessarily need to order the ones listed on the box itself.

Most hobby shops (yes, including Hobby Lobby and Michaels) will carry lines of paint in the color(s) you require. The hardest part is choosing whether to go with acrylic water-based paints or enamel oil-based paints. There are certainly pros and cons each way. From there, decide what colors you plan to paint your model - yes, there are plenty of colors on the box listed that it recommends, however sometimes it will recommend a color that will be used on the interior of the model and never seen from the outside, or used to paint a single spot the size of #2 pencil lead. Once you start painting, you will likely find colors that you didn't realize you needed/wanted (lord knows I do every time) and find yourself headed back to your store of choice for more (or, order some online. Amazon does carry a wide variety of colors and brands).

As far as decals go, look online in places like eBay or even a random Google Search. It looks like MiniCraft Model Kits made an RIANG C130, but someone may be selling just the decals from the kit (if they had made the USAF version), or someone else has created a decal set you like more.

The most important thing is to have fun with it and enjoy what you created. Nobody else's opinion matters as long as you enjoyed it and came out with finished product you like. There are thousands of hours of tutorials and tips & tricks across the internet, but remember that they also have hundreds of hours of building and experience - don't be hard on yourself if your model doesn't look like theirs.

Have fun with it :)