Can an IP be forced to receive data from another IP (specifically IPv6 for both)? If so how does this work, and how can I prevent this from happening to me? Does that have any way to be broken? If so how can it be improved?
Your machine, regardless of whether it uses IPv4 or IPv6, does exactly what it's programmed to do. This means following the TCP/IP (Transmission Control Protocol/Internet Protocol) standard. The protocol has a well defined handshake (starting sequence of actions). If all goes well, the connection is made and data moves.
An analogy is the phone. Your phone rings, but you're not forced to answer it. Likewise, a connection request can come in, but your machine doesn't need to respond to it. This is easily doable with a firewall. From the sending machine's perspective, their call vanished into the void, since no response came back.
Furthermore, you can pick up the phone, but quickly decide that you don't want to talk to the person. This happens when your machine responds to the first connection request, but then responds to the next part of the handshake with a "Hang up, I don't want to talk to you anymore." signal (called a "FIN" packet).
There are other protocols with different ways of connecting, but TCP/IP is how much of the web is served.