For intro games we have broadly used the following:
- Small table, say 4'x4'.
- A battalion of infantry per side plus organic support, so 9 x infantry, 3 x mgs, 1 mortar etc.
- A few tanks, around 3, as everybody likes tanks

.
- No recce, off board artillery etc as that can be introduced later.
- Keep the scenario simple, but with an interesting background story. So classic encounter may not sound fun but it provides quick and easy games.
Hope this helps?