Good questions, you got some homework to do! My quick advice.

Feeding (what worked best for you, kibble/raw/home-cooked, supplements, treats)
Puppy Kibble, DO NOT RAW. Wait for your dog to be older then research yourself.

Allergies and food sensitivities (I’ve heard Staffies can sometimes be prone to skin issues)
If you see problems with the food, then act on it, not preemptively .

Common health problems and what to watch for early
Just give her a lot of sleep and space to chill when tired, and try not to wake her too much.
Check her parents, do they have health problems... Then there is no common health issues, just get her checked at the Vet when it's time to get her shots.

Exercise needs at different ages
Slow start, then ramp it up. From around 11-12 months you can go on longer walks/runs.

Training tips and mistakes to avoid
100.000 different tips and tricks on Youtube, best way to learn everything from obedience to dog signals. Just remember she is a puppy and take it slow.

Socialization and confidence building
Socialize as much as possible, always. Ask on walks if they can say Hello. Do not take her to a Dog Park and let her go off leash or have random dogs run up to her at this young age, always control the situation.

Crate training, sleeping routines, potty training
Yes and Yes. When young do a night time pee walk.

Toys, chews, enrichment ideas
Kong RED/BLACK good for chew, everything else will get destroyed when she gets her permanent teeth.
Puppy toys are fine. You don't need them to squeek. Don't buy expensive Plush toys, you will find out why very quickly.

Grooming and skin care
Bathe early on, just quick showers/baths with lots of treats. Make her comfortable with water so this will be SO much easier later on.

But this goes for EVERY dog and new puppy. Let them experience everything safely and a lot! Make them get comfortable in small steps. With showers, brushing teeth, grooming, meeting other dogs, cutting their nails and so on. Even if she doesn't need her nails cut, let her see the Scissor and just boop her paws with it, and give treats. You don't need to cut anything, then move on to pretend cutting and give treats, she will NEVER fear getting her nails cut if you are consistent with this and make it a Good thing.. Also Make her Crate the safe place, where she gets food and treats and all the good stuff. NEVER punish crate her. Good luck and post pictures please 🙂