i just returned from ecuador & met who id like to marry. if she comes up on tourist visa, can we marry?& what are the best steps to take afterwards?

She cannot use a tourist visa to enter the United States if her intent is to marry you, remain in the United States,  and seek permanent residence. This is considered immigrant intent and is very serious. If the goal is to marry and have her remain in the United States you should be pursuing a fiancé visa. You can read more about the fiancé process at http://myattorneyusa.com/k-1-and-k-2-visas-for-fiancees-and-derivatives.