[Happy days]

Placed an order for 6 poults in July. 6 week old
  This will be my first try at turkeys. We have a shed 14ftx 10 and planning to free range through the day.
Anything I need to consider?

[Richmond]

Height of fencing - they can easily fly over 10 feet. Clip their wings as soon as you turn them out so they can be contained within a grazing area.

Feed dedicated turkey pellet. 21% protein until at least 3 months old, then you can reduce to 18% and finish on 16%.

Don't rear them on ground that has been previously used by chickens because of blackhead (a parasite chickens are resistant to but can kill turkeys).

Other than the above they will be happy with as much space and grass as you can provide. Enjoy them, turkeys are very inquisitive, friendly and rewarding birds, even if they are ultimately destined for the table.

[Happy days]

Thanks,  I hadn't realised they were such good flyers.
There are also chickens free ranging so may need to consider a run instead