In terms of ticket price, unfortunately you couldn't pick a worse game to go to.
People in Philly are very excited about the season. It's a Friday night game. First home game of the season and it's against a marquee opponent. It's going to be a full house for sure, with a lot of excitement.I got these floor seats last year for like $105
each when the C's were in town in December (and there were multiple tickets in this area for similar prices), I imagine this was because Embiid, Noel, and Simmons were all out, the Sixers had the worst record in the East at the time, and there really wasn't much optimism about that team yet. Usually I recommend waiting until the last minute to buy tickets as prices tend to drop, but I'm not sure if that's going to happen here unless Fultz, Simmons, and Embiid all go down in preseason. This one's likely to stay a hot ticket.
When it comes to where to sit, I've knocked out about half the NBA arenas so far, and I think they're all pretty much the same. I avoid sitting lower level behind the backboard at all costs, otherwise I think just about every where else has a good enough view. I'm usually just happy to be in the building though.
In terms of what to do in Philly, besides the historical stuff, they have a few casinos if that's your thing. The King of Prussia Mall is the largest mall in the US, but it's really unspectacular, so I wouldn't recommend spending time there. If nothing else in Philly interests you, another thing to consider is taking a day trip somewhere else. NYC is like a 90 minute train ride away, DC is about 2 hours away by train. Atlantic City is about an hour away by car.