Help for a new owner

[DSRJerry]

I just finished my 1st extended drive in my new to me) 2000 Boxter (300 miles). Things went very well until I turned the last corner 2 blocks from my house when the car put out a great puff of smoke from the exhaust and the CEL started flashing. I limped into the driveway smoking and shut it down. I plugged my Fix'D reader and got the following codes:

SAE DTC Porsche PC Fault type
PO300 62 Misfire detection (sum total)
PO301 508 Misfire cylinder 1
PO307 509 Misfire cylinder 2
PO 303 510 Misfire cylinder 3

I’ve driven the car a total of about 1500 miles since I bought it.

Any ideas what happened and what needs to be done to fix it?

I’m desperate here.