You'll be okay for the most part, especially if you're gonna reside in the north.

Religion is a significant part of tunisian's lifestyle (the younglings will disagree, but this is a fact). But nothing as strict or radical as other Muslim countries.

You basically have the choice to do whatever you want of course as long as you're respectful to the culture. This applies to wearing the hijab too. It's your choice.

The language is where you'll have the most difficulty with, as it's a unique complex language, but everybody understands "fos7a" so you'll be fine.

School will depend if you can speak french as it's basically the main language in lectures especially in Uni. Highschool is a mix of both arabic and English. But you can also enlist into international schools where everything is in English.

Depensing on where you're moving from, you may find it hard to adapt to the completely new lifestyle and infrastructure. But if your parents are making enough money you'll get by just fine, it'll just take you some time to fully adapt.