Soon to be first time puppy owner (any advice appreciated)

I'm 17M and my parents are giving me a dog for my birthday. The breed will be a dachshund, minature or standard (undecided) and around 12 weeks old. I've heard puppies need constant attention and surveillance which will be no problem since I do online schooling.

I have a few questions concerning how I should care for the dogs hygiene and well-being listed below:

1. Where should I put my puppy's play pen and should I have it sleep in a crate or an open space within the playpen?

2. Should I buy something like a heating pad for my puppy (winter in a few months) it can get around 5°C at night.

3. What age do I start brushing their teeth and what's a good australian dog toothpaste brand?

4. When do I start bathing my puppy and how often, warm water I'm guessing?

5. Should I visit the vet immediately after getting the puppy or wait a few days?

6. What can I do with my backyard to make it a safe space for my dog?

7. I've heard puppies can be pretty destructive how can I minimise the damage?

Thanks for reading and do not worry I'll be asking my vet a TON more questions I just wanted some general advice and info from puppy owners.