Hi Mary and Welcome
I see you are new here, the first thing to do is follow the link in the comments on your profile "New Member How To", lots of good start up information will help you.
Then, start entering the information you know about you ancestors - first your parents, then grandparents, and so on. As you work on those profiles you will become familiar with WikiTree.
The way to attach to someone 6 generations back is by building up to that generation - finding and adding ancestors.
Another hint is to use the "Find" menu and select "Surname" then follow the instructions. I am sure you will find many Camerons and Burns already here.
Please always come back to G2G with any questions you have. Hereʻs another link that might help. https://www.wikitree.com/wiki/Help:How_to_Use_WikiTree