As a rule, the Sunday night party is on Kim Sha Beach. There is a large lot next to Royal Palm and parking has been available there for a charge. My personal advice would be to get there later afternoon, get a spot out near the road to avoid being blocked in and spend some time walking around. Get something to eat, etc. Unless it is a designated parking spot or lot, a lot of cars get towed the night of the party.
Looks like Saturday night is on Kim Sha this year also. Same advice as above.
There is usually a party Thursday night at PDP and there is ample parking there.
I have never been to the party in Marigot and from what I can tell on the website, there is NOT a party there this year.
The party in town is on the Boardwalk Friday night.
Wear comfortable shoes, be prepared to walk and experience large crowds. Be aware of your surroundings and leave the jewelry at home.
Here is a link for the parties.
Regatta Parties