Nice start. It's imaginative--using Fawkes against Dumbledore's meddling. That's new.
If Harry and Hermione go to Hogwarts, that'll be the main conflict. Sirius, Remus, and the Grangers have managed to keep Albus out of the kids' lives so far, but their luck is bound to run out. There's going to have to be a confrontation and I think it's going to happen at Hogwarts.
Good job.