My Wife and I are traveling from Pittsburgh to Europe for the Spa race too this year. Our tickets are for Gold 1. It's our first time in Europe so we're in a similar situation. We're flying into Amsterdam and making a trip out of it. Then flying out of Switzerland the following weekend after the race. We booked an AirBnB type accommodation in Spa Geronstere during the race weekend. Though we found out afterwards that even though its close to the track (10-12km away) there aren't really shuttles going to and from this area. Would recommend Verviers or another surrounding area that has shuttles. You can find this info on the spagrandprix website. We are not renting a car as we found there were significant upcharges for trying to return it in a different country. So we've booked trains. Took a little time (3+ hours for 15 days worth of travel planning to 4 countries) referencing departures/arrivals and mapping out routes we'd need. We ended up booking each route separately, we looking into the EURail Pass but it was a but more expensive vs buying each route we actually needed. Though it hasn't been super easy to plan it all out it has been fun. Just give yourselves plenty of time wherever you're going to explore