The philosophy of Tiny core that is it's tiny and you add the components your self.
Like openssh or dropbear so you can ssh to it and you can load these packages with the tce-load command. And dont't forget to take a backup of your running config, with filetool command.
You can also edit the inittab to support for serial tty via uart. It's little more tricky because you need to change the initrd.
And you also need to save the keys when installing openssh or dropbear, this can be done with filetool.
And this forum is here for you and help, but you have to try out little before asking, we can't share a completed guide how to setup the way you want.
The first setup with tc or picore has to be with a head, when you get a gist of how tc works you can change the behavier so the setup can maybe be done without head.