Budget for a pinpointer (a small handheld wand). It will save you hours of digging by locating the target precisely in the hole. To help you find the perfect machine, could you tell me: What is your approximate budget ?
If you want to hold the detector in your hands before buying, visit a local brick-and-mortar store.
Ensure the seller is an authorized distributor so you are covered if the electronics fail.
You can join local detecting clubs through these shops.