Your dog NEEDS to pee and poop, there’s simply no way to avoid it! The solution of course is teaching your dog when and where to go. The only way to prevent mistakes and put potty on cue is regular confinement sessions.
The easiest way to get a dog to do something is to show them, the easiest way to show them is with a lure and the easiest lure to use is a food treat.
By using a lure to illicit the correct response, you are already training them to respond to the movement of your hand. That makes it easy to train them to respond to a hand signal that can then be used at a distance.
Once your dog has learned a command, you want to start phasing out the use of food as a reward. Praise & pet them when they do something right, but only give them a treat when they perform exceptionally well.
The easiest lure you can use is a food treat. Dogs are naturally attracted to tasty snacks, and if your dog does something you like, it makes a very handy and effective reward. Just make sure you slowly phase it out before it becomes a crutch.