The best chinchilla supplies tend to be from vendors online, there is a list of them in the classified section, as well as the banner ads on the top of the forum. If you are a bit more specific as to what you want, like the best place to get hay, or the best place to get fleece items, etc. we can point you in the right direction.
Yes regular popsicle sticks, like what you would use to make popsicles (food grade) are fine. They do splinter though, so they can be debatable in terms of safety, so it's something you do need to watch to make sure they don't hurt themselves.
The best rundown of new owner basics is found in
General Chin FAQs Also check out the FAQ under other sections as well, like housing and supplies, diet and nutrition, and new owner. Most questions new owners have have already been answered, but also you will find answers to things you didn't think to ask.
Aside from that the best advice is, take time to do lots and lots of research. This forum has tons of info from people in all aspects of the chinchilla world, breeding, showing, ranching, and just plain pet owners.
If you already have the cage all setup take a pic and link it on here, we can also help you make sure that it's got everything you need and is good to go for your new chin.