"No targets specified and no makefile found."
Based on the error feedback I suppose that you have multiple makefiles for different platforms in the source package and have to specify which one to use, or these are created by the config script when you specify the system name. I never compiled beryl from source, but this kind of errors are not unique to beryl, and in fact they are no errors. It's missing input data.
Find the makefile for your system (most likely Linux or UNIX or something like that) and rename it to 'Makefile', or pass the system name to the configuration script like './configure <your-system-name-here>'.
I'm surprised that the documentation doesn't provide info about this. Usually the README or INSTALL files have all infos needed.