You don't have to panic. Yes, Google will be tracking but, by and large, only if you login to one of your accounts. Not as if they hadn't been before - but now it will be a bit more thorough. It will gather a "dossier" on what you do across its platforms - which it will enable it to suggest much more pertinent items of interest. For example, suggesting a YouTube video that relates to searches you did.
If you are concerned over your past web activities- go to www.google.com/history and login with your gmail account. Simple click "remove all web history." If you want to know what Google assumes it knows about you - you can check at www.google.com/dashboard. Again, you have to login. You can delete all your past search activity.
Cavaets: Tracking of activity is separate for the Chrome web browser. If you don't login, then Google still tracks by IP address or web browser identifier. But that would only point to a machine, not a person. Also, smartphones with Google's Android software will also use the new comprehensive tracking.