昨天电话面试，今天早上收到positive feedback。请问怎么回复？

昨天和hiring manger电话面试，早上收到公司recruiter的邮件，说feedback is positive. 还问我 “what did you think this opportunity?" 邮件里还说 “we are still working on first round interviews so we won't probably have a clear "next step" for you until a couple of week." 

请问大家，我应该怎么回复？谢谢。