, you dont have to do bayat to start the basic zikr of the naqshbandis, I attend a majlis of a naqshbandi sheikh and I am not bayat, i do the zikr (I have done it at home too once or twice and the sheikh encourages it as a daily amal). There is a poster on the wall of the khanqah which explains in detail the method of zikr and encourages everyone to do it. you have been contacted by the website and been told to start the zikr, so I think you should start doing it while you continue your search for a sheikh. Allah knows best