Re: very first lesson plan
Your question is almost impossible to answer without knowing something about your students, and about you. How much, if any, knowledge of English do they have already? Are they doing this as seriously as if they were paying a lot of money for a course, or is it just a bit of fun? Have you ever taught anything before? Do they/you want to use a course book?
Even if you were to give detailed answers to those questions, it would still be difficult for us to answer.
I would suggest - and it's only an idea - that you spend your first session discussing with them them what they hope to get out of the course. Your approach will vary, depending on whether they want to take a recognised test (TOEFL, for example), get on in their jobs, just converse with English-speaking friends, etc.
Please do not edit your question after it has received a response. Such editing can make the response hard for others to understand.