To build from the git repository use:

$ autoreconf -fvi
$ ./configure && make

Now you need to generate a certificate. E.g.
$ certtool --generate-privkey > ./test-key.pem
$ certtool --generate-self-signed --load-privkey test-key.pem --outfile test-cert.pem
(make sure you enable encryption or signing)

To run the server edit the src/sample.config and then run:
# src/ocserv -f -c src/sample.config