We took on a rescue dog last year - she was just 6wks old when dumped by her cruel owners after they 'bodged' her docked tail, which was obviously illegal at this point.
She ended up in rescue kennels until muggins, ie me, came along and was told about a lovely little dog in desperate need of a loving family home.
I was taken to a back kennel, out of the public eye, and shown this scruffy tiny little thing looking very sorry for herself, surrounded by large noisy dogs in kennels either side, with a bloody messy stump for a tail recovering from its bodged attempt at being docked.
I immediately decided to reserve her having looked into those big brown eyes looking up at me.
At ten weeks we brought her home. She'd had one lot of jabs and was due to have her second lot in two weeks, and a week after that she could explore the big outside world.
During that time we bought a crate for her. She took to it straight away. We filled it with some toys, her bed from the kennels, her chews, water etc etc. We covered it with a blanket (to keep her warm) and here we are a year later and she still goes to her crate when she's had enough of being chased around the garden by the kids or simply wants to have a kip.
Having the crate also helped us with toilet training because rarely does a dog mess in its 'space'.
At night the door is kept shut on her crate because we have cats and she'd spend the entire night chasing them around the kitchen. During the day the door is left open and she can please herself.
Springer Spaniels are lovely dogs 2sugars but they have been known to be quite destructive so definitely a good idea to get a crate.
Do not let your puppy out on a lead for a walk, other than in your garden, until a good week after the second lot of jabs. They are not fully covered until then.
As regards you going out - there is no hard and fast rule as to how long you can leave your dog in its crate for. Whatever the dog is happy with as each dog is individual. Re grocery shopping? Just do it on the internet if you're that worried!