Hi there
There are campsites for tents at Ballintuim (between Bridge of Cally and Kirkmichael), Nether Craig (north of Alyth) and New Alyth (Bridge of Cally takes caravans only). There are bunkhouses at Spittal of Glenshee (both in the hotel and at Gulabin Lodge). However, wild camping is allowed anywhere that access rights apply. Please read the related posts
here. Enjoy your hike and please tell us how you found the camping after you get back!