Can you be tracked if you use VPN?

I've been hearing a lot about VPNs and their ability to keep my online activity private. But, I'm curious - can I still be tracked if I use a VPN? I understand that VPNs encrypt my data and route it through a different server, but are there still ways for someone to monitor my online activities, even with a VPN in place? It's important for me to stay as anonymous as possible when using the internet, so I'd like to know if a VPN is truly effective in hiding my digital footprint.