Paris Visite is mostly a tourist trap. It only comes in zones 1–3 or zones 1–5, while all major tourist attractions are in zone 1 except for the Versailles Palace which is in zone 4, and Orly airport is in zone 4, Roissy airport is in zone 5, so most tourists will want the more expensive zones 1–5 pass. The Parc des Expositions in Villepinte is in zone 4, the one at Porte de Versailles is in zone 1.
The current price is 22.85€ for 1 day, with decreasing daily rates down to 59.50€ for 5 days. This is rarely worth it if you're using it for transport alone, only if you're interested in the meager discounts.
A day ticket for zones 1–4 costs 11.20€, and is not valid to travel from or to the airports. It won't be useful for you, it's only worth the price if you make at last three cross-zone trips or have bus connections. A weekly ticket for zones 1–4 costs 37€ (including the 5€ cost to buy the reusable physical token), but this only runs Monday to Sunday, so it isn't applicable to you.
A single ticket between Paris and the Parc des expositions in Villepinte costs 4.20€. A ticket for the Orlybus service costs 7.50€. A ticket to the station serving the Versailles Palace costs 4.20€. That's 48.6€ plus a few tickets within Paris: 1.70€ for a single ticket, 13.70€ for a book of 10.
So for you, if you go to Villepinte three times and visit the Versailles Palace and move around a little in Paris, a Paris Visite pass is the cheapest pass. If you don't go to Versailles and stay put in Paris then the Paris Visite pass is more expensive, but only slightly. If you're going to the Parc des expositions near Porte de Versailles and not the one in Paris, get a book of “ticket t+” (valid for one Paris metro trip or one bus/tram trip with bus/tram connections) and single tickets for the airport (and Versailles if you want to go there).