In the olden days, for a new member to join a Rotary club the unofficial rule was, expressed in simple terms, he should be "somebody who is in a position to hire and fire". Yes, 'he'. Thankfully, around 1987, the 'he' was expanded to also include the fairer sex. There were lots of other rules too, for example, weekly attendance at our meetings was considered to be just about essential.  
 
These days, the rules are very simple and straightforward.  Here is an extract from the Membership section of our Club Consitution of 2019 (1):
 
Section 1 — General Qualifications.
This club shall be composed of adult persons who demonstrate good character, integrity, and leadership; possess a good reputation within their business, profession, and/or community; and are willing to serve in their community and/or around the world.
 
That should be simple enough. In other words, the majority of people in your circle of friends, in business, your suppliers, your customers qualify. Rotary is absolutely non-denominational, absolutely gender-neutral. All we ask for is of good character, has integrity, and a good reputation.  Start making a list and invite them to come to one of our meetings.
 
(1) Members can download the Club Constitution from our website: (you need to login to the Member Area, top right of home page), then select Organisation, Documents and search for Constitution.