Myself, been there, done that many times.
I went to some of those Grand Prix events in the eighties; that was good fun camping in the infield.
The later WSB races were some pretty good action, too. The crowds were smaller and Laguna Seca Raceway was easy to manage.
Now as for last year's MotoGP event, I went to that, and as some have suggested, it was a great time and a gargantuan cluster-eff at the same time.
I recommend NOT camping on-site unless you can tolerate primitive dirt camping.
Maybe being mid-forties that sort of thing ain't as much fun as it used to be. Not to mention that all of the premium and reserved camping sites are long gone.
[Assuming you're not interested in any of the Friday or Saturday events] My recommendation: Book a hotel room for Saturday night, NOW, as close to the track as you can get. I ended up in a place called Santa Nella an hour and a half away but that was my fault for procrastinating. But it didn't matter because I was mobile, wasn't going back there at the end of the day.
On Sunday morning get to the track as early as possible to avoid car traffic. Some hell on wheels action may be necessary to get through.
YMMV.
Then, as you're going up the hill from the highway to get to the gate, get on the shoulder on the right and pass the cars. All the bikes do this.
Once you're in, park wherever and you're all set! Pack in your own water, food and beverage if possible. Sunscreen, portable chair too.
After the races are over, plan on leaving the area and getting a hotel a few hours away unless you can get home that day. One last thing, buy tickets now, last year even GA tickets sold out.