Any suggestions on what to do as far as a coop? Is it necessary in this situation?
They need somewhere to go when it rains, somewhere to have shade from the sun, somewhere to sleep at night. A coop can provide all of these things, even if the door is always left open.
Trees can be good shade by day, chickens might sleep in them at night--but most trees are not very good shelter when there's a hard rain.
A coop can also provide protection from many kinds of predators, if the chickens are securely shut inside it. (This requires closing the door. One of those automatic doors could be a good choice.)
...concerned about owls and hawks...
Because owls attack from above, the chickens will be safer under a roof at night. Because hawks attack from above, the chickens will be safer under a roof or under trees in the daytime.
Can animals dig under the fence?
Probably.
And raccoons are known for being able to climb just about anything, probably including your fence.
I cannot be there everyday as it’s across town. I can be there every couple days though.
When you first move the birds there, try to stay for at least a bit and watch them--some kinds of problems show up very quickly (if they dump the water bucket by sitting on the edge, or walk through a hole in the fence that you had not noticed, or fly over the fence the first time they hear a strange sound.)
If you can check them every single day for the first few days, that will also help--that way any problems that happen during the first night will be noticed before the second night, and if they drank all the water up one day you will know to give them more for next time, and so forth.
It would be good to check them soon after the first rain, too--if the feeder leaks and all the feed is wet, you don't want to leave it that way for too long! Freshly wet feed is fine for them to eat, but most feeders don't work right with wet feed (it gets stuck where they cannot reach it), and wet feed will spoil if it sits around for too long.