American Tax Question (Brussels)

Hello everyone!

Expat tax question coming your way :)

I'm an American with Belgian residency. In the next month I'll be moving to France and plan to continue working with international clients. I would like to set up my freelance copywriting business/activities, but am wondering if anyone has experience doing this? Is it best to go for the American set-up or am I obligated to set up in Belgium due to my residency here? If you happen to know a tax expert with expertise in expat matters that would be great as well.

Thanks for your help,