I'd start by going here and running the free test "All Service Ports": https://www.grc.com/x/ne.dll?bh0bkyd2
If your router (assuming you have one, if not, you should) is set up properly you should be in full stealth mode. The only exception would be for a port you opened intentionally where you understand the risks involved.
If your router is doing its job, the short answer to "Could you still be hacked?" is "Only if you let them in yourself", either through falling for something like a phishing scam or collecting a virus which opens a back door.
In brief, a good router will barricade the walls for you. After that, your main vulnerability is through user error which inadvertently opens a door from the inside.