It's already installed with your Qtel sim card, but is very expensive (10 QR/MB).

It's better to get a data plan sim card. A gigabyte of donloads/uploads costs 100 QR/month and unlimited is 400 QR/month (way too expnsive!). With a data sim card, you can't make or receive calls though (sms works)

For settings, go to the qtel site.

Good luck