So parking is difficult in this area of San Diego. I called the Hotel and they said that this is how the parking works.
At the Hotel:
Self Parking- $8 first hour $4 every hour after that with a max of $24 per day. There are no in and out privileges unless you are an overnight guest. If you purchase food or drink from the restaurant or bar you can have your ticket validated for 1/2 off the price of your parking.
Valet Parking - $10 First hour $6 every hour after that with a max $35ish per day. Same no in and out but the 1/2 off deal above applies as well.
Other than that there are not many other options for parking outside of that if you are driving solo. There is some parking in the Harbor Drive Park, but every time I have ever been down there parking is not to be had, you could try though. If you are carpooling the best spot would be Liberty Station. It is on the west side of the bay has some great places to eat and plenty of parking. Liberty station is on the way from Hotel Circle in Mission valley if you are staying that way. Mass/public transit Is likely not a good play as there is not a close trolley stop and I have no experience with the bus system.
I am not sure how many people are staying in the area from out of town, but Mission Valley has a lot of hotels. There are a good number of hotels closer, but I think they are more spendy. Most folks are going to pay $75 a night for a cheap room anyways, I would just pony up for the hotel PV2 is in just to make it easier.