Canada visa refusal, insufficient travel history

There are several things you can do.

1) The visa refusal letter doesn't tell the whole story. What you ideally want to get are the actual case notes from the officer processing your application. These will tell you which areas of your application were strong and which were weak (maybe the problem is more than just travel history). The process to get these notes can be lengthy and complicated, it's described here (if I'm not mistaken), but you need to be physically present in Canada to make the request, so you'll have to use a Canadian representative, there are some companies that do this like this one. But please do your own research, I never actually used this process outside of Canada, nor this company.

2) There is no legal requirement for you to have a history of international travel to be admitted into Canada. If the visa officer saw a problem with your lack of travel history, this probably means that the rest of the application was weak. If there's anything you can do to significantly improve some other section of the application (ties to home country such as family, pre-purchased airline tickets, proof of finances, etc), it can help you.

3) Think about building up an international travel history. Of course, Schengen or USA would be ideal, but from what I've seen and heard anecdotally, almost any international travel is much better than no travel at all.

4) Finally, consider getting professional help with your application. A lawyer may be very expensive, but in Canada there are also Registered Immigration Consultants that may be cheaper.

Sorry to hear you didn't get the visa - the process can be frustrating and lengthy, I wish you luck!