When you choose a team at the start to manage it has a "chairman status" which says how likely they are to be sold and how quickly this might happen.
Chairmen whose status is set to "Loves club" aren't likely to be selling anytime soon, but chairmen with "will listen to offers" are more likely to sell around the start of the game.
Unsure which teams are likely, but in England you need to go down to about the 4th tier before you find a club, there is only 4 or 5 clubs in England with a chairman who is looking to leave.
Hope this has helped.