There are some payed plugins(
WP-Scipt,
Mechbunny) you can use that will auto post to your tube, but beware that adding duplicate content hurt SEO, if that is your source of traffic.
If you want to get started for free (except hosting): You could add new videos manually if you have the time or mass import with .csv files for free.
Tutorial videos for these methods here. Once you have mass videos you could make wordpress show random posts on first page to show your visitors something new all the time.
If you need a free tube theme please check out
Porn Theme #4.
You can use Hostgator but
Dreamhost offer WordPress hosting 5 times faster then regular shared hosting and costs just a little more.