welcome janicem to FT.
flying coach internationally is not the end of the world, but it can be challenging to squeeze into the seat if you are tall or weigh more than 200 pounds (obviously this is a big generalization).
if you cannot afford to buy a business class ticket (and not many of us can or are willing to -- it really is a lot of money to spend for a few hours on a plane) then your best options are to buy a coach ticket and try to get your hands on upgrade vouchers or lots of frequent flier miles that can then be used to upgrade tickets to business.
Although the airlines (and some of the folks here on FT) frown on this practice (I personally would not do this but then again I can (and have many times) suffer through 20+hours of coach if I have to), there are ways to BUY upgrade vouchers (for example, see eBay), and certain airlines (such as American and United) will allow you to use these upgrades on practically any fare. The caveat here is that the airlines can revoke your frequent flier status (or maybe even worse) if they catch you buying these certs. But this kind of thing appears to happen all the time (for now, at least)
The other option is to get your hands on more miles. There are many ways to do this. And this site is the place to learn about those ways. Right now, the best airline to accumulate miles without flying is American. Check out that board and you'll read about the current 20K for 20 partners promo (very doable for a modest out of pocket investment), the 10K bonus signup for applying for a Citibank World Mastercard for $50, and, of course, I should not forget that you can buy (and donate) food for a lot of miles. Once you get these miles, you may be able to upgrade your coach tickets to business... Hope this helps.