Hi,

Can I Switch to a new plan, for what things, I need to care of?

Regards,

Well, it depends, whether you want to Upgrade or Degrade, In case of Upgrade, there will some new features available that may not be there in your old plan e.g increased disk space more bandwidth and many more.
But, when you degrade you need to check which of the resources your websites are using, and whether those resources will be there in the down plan or not.