Potty training UPDATED

So we got this adorable puppy yesterday and his previous owners trained him to use puppy pads so he’s not trained to whine or anything when he has to go outside and this is our first time training an actual puppy and need advice on how to potty train him. We’ve saying ah loudly when we catch him going potty but when we take him outside he will not go potty at all. We took him and our older dog out to the lake for a hike today and he didn’t go once and we were there for almost two hours and waited until we walked into the front door to go potty and does this every time we take him outside. Any advice about potty training would greatly appreciated

First

pic when we got him yesterday and second is after the lake trip! He got super muddy with all this Oklahoma red dirt

Update:

So we got puppies pads and have been taking him out with the other dog and absolutely nothing is working! Still no warning signs for when he’s about to go pee and he refuses to go in the pads. We’ve been kenneling him when we can’t keep an eye on him and take him out as soon we left him out of it and he will not go potty outside