Well, only defining commands \name etc. is only the first step. You need to define where should it be printed, for example inside \maketitle, how to layout the cv, font, fontsize etc.
That is at all not so easy as it seems you think.
With \newcommand{\name}{Firstname lastname} you can define a command \name printing "Firstname Lastname" where it is used. With \renewcommand{\name}{John Doe} you can change the placeholder to an (perhaps) real name.
If you are realy interested in learning writing own classes please read and study first clsguide.pdf. You can read it with typing texdoc clsguide into your console/terminal. Then there are some questions here about classes, for example Pass parameter to class or creating a class or package etc.
Be prepared it would take a little bit time (or more) to learn what you have to do. Look into other classes what they do.
Or look for example on CTAN for existing classes to create an CV, for example moderncv.
resume.cls? Or is this some other class that already provides\name,\addressand\phone? – Werner Dec 10 '15 at 07:14resume.clsmyself, so I guess I have to define some placeholders in my class and overwrite them with\name{...}in my .tex file. – Jamgreen Dec 10 '15 at 07:22.clsthat you can access/use in your.texfile. But you seem to be asking to create commands in your.texfile that will be accessed/used in the.cls, which does not make sense (or, probably, I can't see the sense of what this is supposed to accomplish). – jon May 20 '16 at 02:15