An old fashioned way to get your SE on the internet would be with a modem. There are Mac 56k modems for sale on ebay, and there still seem to be dial up internet service providers. Though it would require land line phone service, which I guess many people don't have anymore.

An alternative is an Ethernet to LocalTalk bridge. On model seems to still be for sale on amazon. But I think additional software is needed to get internet access over it. If I understand correctly that is what Mike Fort's gateway software is about.

And another alternative is to use an emulator. For example, I think Basilisk II has internet access. And the emulator I maintain, Mini vMac, has LocalTalk emulation, written by Mike Fort, in the development branch, which with the gateway mentioned above, should eventually allow internet access.