Yes, you can use the information on your Ancestry family tree. To do this, you need to create a gedcom file. Have a look at the gedcom help pages and come back here to the forum if you have any further questions.
https://www.wikitree.com/wiki/Category:GEDCOM_Help
The gedcom file will create a report that you can go through and accept or reject potential matches. When you finish doing that, you can add any remaining people.
I strongly suggest adding a few profiles manually first so you can try out that process. Then if you decide to use a gedcom file, start with a very small file so you can try that process too.
On Wikitree, we are all collaborating on a single tree so eventually you will connect with existing profiles so you may find that you don't need to add that many profiles manually.
If you have any questions, don't hesitate to ask!
