If you've scheduled a phone session, you will need to call the number given here at the appointed time:
The number is in France, so the + means that you need to add the digits needed to get out of your own country. For example, in the U.S. the digits are 01, so the number is 01-33-561-442-264. Or, from most European countries, it is 00, so it would be 00-33-561-442-264. From inside France one just adds a zero, so the number is 05 61 44 22 64.
If you're worried about the phone call being long-distance and expensive, you might look at your long distance plan, to make sure it has reasonable rates. 10-12 cents per minute would be a reasonable plan from most countries, with AT&T for example. You can easily find plans down to 5 cents, which is about the same it would cost you to call somebody in the next county.
If you find you have a bad long-distance plan with your phone company, you can in many places call other numbers to instantly get good rates. Like in the U.S. services like 101-6868, which is 10 cents from the U.S. to France.
Or, in all countries you can find calling cards with good rates. Sometimes rates much better than your phone company can provide. Like check out bigzoo.com. 2.8 cents to France. They're maybe more likely to have trouble with the quality than if you use AT&T, but it might be worth the risk.