Last did this in 2017 with my oldest as part of his graduation tour.
We flew from MAD-PNA on Iberia and PNA-BCN on Vueling. The latter flight was a great option and only cost us $30.00 per person with the caveat that the flight only happens a few times a week and just so coincided with our stay. Pamplona is pretty much in the middle of nowhere in the north of Spain. I don't have experience with the trains, or driving there, but the flights were cheap enough not to worry about it. I'd try to frame a trip around this for dates. We had round trip bus service to/from the airport through a charter company.
We stayed at the Holiday Inn, which is outside of town. Mainly because I could use points, it's small-town Spain and the redemption rate was cheap. Cabs were plentiful. It was fine for our purposes, but just know that English isn't widely spoken outside of Barcelona/Madrid/Tourist cities. You'll remember high school Spanish in no time flat to communicate enough.
We had 2 days there: One to observe and one to run. I booked a balcony in someone's apartment through a service for the first day. Easy meetup with the host and they had the commentary on the TV. Prices vary but honestly I can't see much of a difference on what level you are on. All views are unobstructed albeit some may have another few seconds of action. If you want to see the "crashes" ala Nascar, book something closer to Deadman's curve or the stadium where people pileup. There is a secondary running of a few bulls to clear the street.
On the second day I ran and my son filmed. The tourists are at the front, and may never see a bull until the stadium, the middle are more adventurous tourists that want a story and the locals/crazies are at the back. I was mid-pack. (Chubby guy) Before the festivities, everyone sings a song of prayer to San Fermin. Then they shoot the rocket and then the gates open. You have about 3 minutes to get to the stadium if you're on pace with very few places to exit beforehand. You can either stay in the dirt or go into the stands depending on how close you want to get to the bulls. You either stay for the fights or exit the stadium. We did the latter.
There are small festivals going on, but the tourist thing to do is to go to Cafe Iruna and get churros and hot chocolate that's thick enough to soak up the churro. You'll want a second order of these. Sangria is plentiful but none of the food really stood out. If you don't like ham, you're SOL. IIRC, they have the normal chains like BK and McDonalds.
We had fun but it's not something that I would go out of my way to do. It's kind of like spending a lot of money and standing in line at a theme park just to ride 1 roller coaster.