This is my first year trying to go to Coachella so I am very uneducated but I saw on stubhub and other websites like stubhub that tickets were on sale can I buy them from one of those websites or do I have to buy my tickets from this website only?
Any day/week/month now the lineup and ticket sale info will be announced on coachella.com. Just follow the instructions. If you are unlucky you can always try a ticket reseller like StubHub later. Be very careful of craigs list and eBay sellers - people get ripped off doing that every year.
You can't buy parking or camping passes from StubHub. Finding a place to stay can be challenging and expensive. If you can afford it the travel packages that include festival passes, hotels and shuttle passes are pretty convenient.
Chances are you won't get tickets in the general sale. If you're a local then your best bet is to be patient and watch craigslist and facebook. Other ticket broker sites are always going to charge a large premium.
Also, the closer you wait to the festival, the more money you'll save. Keep your eyes open for a thread that tracks prices, I think it was PlayaDelWes who ran a thread last year. He had the prices of 3rd party tickets and did a number of statistical breakdowns like which day was best to buy. Everyone goes Coachella crazy when the lineup drops and wants to go. Then March and April roll around and real world obligations bring a large number of people back to reality and tickets flood the market. So unless you're from across/out of the country and don't want to book flights without a ticket, the best advice is to simply wait.