Haven’t read all posts so may duplicate here but this is our experience with our cockapoo:
Firstly, do not underestimate how hard the first few months will be. Puppies are hyper, cry and bite/nip. All are normal and in our experience did pass.
We crate trained from day one because we weren’t comfortable we could keep him safe 100% of the time with free reign of the house if he wasn’t being supervised. We agreed from the beginning that we did not want the pup sharing our bed and having a nervous child we do not allow him upstairs. We’ve therefore got a gate on the bottom stair.
We took ours out through the night to let him pee and popped him straight back in the crate. It did not take long for him to be able to go through the night and he stopped whining at nights after a few nights.
Children - we have two boys, one who was the driving force behind the dog in the first place and the other who while he liked the idea of it was scared of dogs. He loved our pup from day one but because he jumped and nipped he didn’t want to be with him. This is why a crate was essential for us, we needed to know we had somewhere safe to put the pup when our younger boy was about. It did not take long for them to bond and him to be fine, they are now best friends but that only happened once puppy teeth fell out and he stopped nipping. The confidence my younger son has with him now is amazing.
Children also leave stuff lying about the house. No matter how often I tell them not to leave food lying around, they are 10 & 8 and do forget so we do have to always be alert as to where the dog is and what he’s after. We often find him in their playroom sniffing for dropped food, we’ve also found him in their rooms choosing which of their stuffed toys he wants for his after someone has left the gate open (in fairness he never destroys them!).
Make sure you have plenty toys and chews for him. Always have one to hand so if he starts chewing on you, you can swap your hand out for a chew! We also got puppy chews like beef pizzle that he loved and kept him quiet for hours!
Socialisation - this one will be tough for you but just get him in your arms when you are doing your daily walk (if you are doing a daily walk) and get him used to roads and noise. We also played sounds through Alexa to get him used to other noises.
Training - we went to puppy training classes, you may need to substitute that for online advise. Get the whole family involved so pup listens to everyone. Make sure you are consistent with it. We use dried food and after a while we stopped feeding at regular intervals and now measure out his daily allowance and use food to train. If he wants food he works for it to make it rewarding for him and to make training easier ( eg rather than breakfast he’ll spend 20 mins doing sit, down, stay etc and get the equivalent food as a reward). I get the kids involved in this and make it fun for us all. This has also made feeding much easier as Cockapoos are known for fussy eating and before that we spent ages getting him to eat anyway.
With regards to your breeder, whilst only 5 miles away, the guidance is that they bring the pup to you. If it was me I’d be doing that rather than going to get him but that’s your call on what you are comfortable with. If you are in any doubt at collection over the breeder walk away.
There are lots of Facebook pages for Cockapoos. The British Cockapoo Society is one that is good and depending on where in the country you are there may be a local one. I’m in Scotland and there’s a great local one.
Grooming - make sure you have a good slicker brush and metal comb and brush lots. Try to avoid matts if you can - you should be ok without a groomer just now and hopefully by the time you need one they will be back open.
Sure there is lots more I could tell you, but over all our dog is amazing and our family love him to bits, we’d not be without him so enjoy your pup and accept that the first few months will be tough!