Red Sox are always a sellout but you can likely get tickets via Stubhub.
That game will likely sell out as they are rival teams. Single game tickets have not been released yet on Yankees.com but there may be some tickets available on StubHub (from season ticket holders). Your best bet is to sign up for email updates on yankees.com and you'll get a notification when the single game tickets are available
They may sell out as they are big rivals. For best selection but ahead of time. Otherwise you may not have a good selection of seats.
Buy ahead of time.
Sign up for ticket alerts on the Yankees website so that you know just when tickets go on sale.
Get tickets as soon as you can. This will be a very hot ticket.
Thanks for all the tips everyone!