Gino, it depends on what your students know. If they know basic math, you can draw supply and demand curves. I remember one of my first lectures in economics (it was already master program for people having university education but not in economics).
Professor has drawn the indifference curve between demand for gulyash (food in Central Europe) and beer. Try to be minimally mathematical but at the same time intuitive and culture specific, so that students feel what it is about.
Students in the 1st class do not know neither perfect competition, nor monopoly. This will come later. First students should feel themsevles as economic actors. To feel that it is stupid (having $10) to spend in supermarket $9 on tequila and just $1 on bread. Equally stupid to sell your output (for example, cooked food) at the price below the sum of input costs. Students should feel the concepts of utility and rationality first - it should become intuitive in their brains. If you start with the formalism of convex and concave functions - students might get lost.
This was about lecture 1. The whole course in microeconomics can clearly contain more: equilibrium, perfect competition, monopolistic optimization, oligopoly. I was following intermediate book of Hal Varian. It may be too little or too much, depending on students' strength.
Currently, my university has a Principles course in Macro and a Principles course in Micro. Students can take either course first, even tough the Micro course has a lot more graphs and math. Next year, we are combining both of these courses into one "Principles of Economics" course. Half of the course will include Micro topics like supply, demand, elasticity, competition, and consumer behavior. The second half of the course will have Macro topics like inflation, unemployment, GDP, fiscal policy, and monetary policy.
For an introduction course, my advise would be to limit the amount of math and complex graphs. Keep it simple and teach the basics.