I think what you are asking is can you transfer your FamilyTreeMaker file to WikiTree? If so, the answer is yes. You will have to export your FamilyTreeMaker file as a GEDCOM. (Go to FILE -> EXPORT) When the pop-up comes up about password protection, just click CONTINUE. You do NOT want to export your entire file, so on the left side of the dialog block, mark the radio button next to Selected Individuals. Choose whoever you want to be your focus person, then who else you want (ancestors, descendants, etc.) Try to keep your GEDCOM small. You can upload a file of up to 5000 to WikiTree, but you do NOT want to do that, I assure you. It's best to keep your upload, especially the first one, at 100 individuals or less. As you select the individuals in FTM, you will see a count of how many individuals will be included in the file your export. Once you are satisfied with your selections, click to apply. Now, at the top of the dialog block, where it says Output Format, click and scroll down to GEDCOM. (I uncheck all the options to include.) Click OK. Make note of where this file will go on your computer so you can find it.
On WikiTree, Click on the MyWikiTree tab and scroll down to select GEDCOMs. Click on choose file. Find the GEDCOM file you just created with FTM then click to upload.
Then you wait for a little while for the GEDCOM file to be processed. You will get an email from WikiTree when your GEDCOMpare report is ready.
The next step is to process the GEDCOMpare report. There will be a link to it in the email your receive. You will be comparing the individuals in your file to individuals who are already on WikiTree. For potential matches, you will either accept or reject. Once you have examined and decided on all the suggested matches, you will get "ADD" buttons for everyone in your file who did not have a match. You can use those "ADD" buttons to create profiles. Data fields will be pre-filled. The narrative biography will be a bit messy and will need to be cleaned and formatted.
There is a help page for processing the GEDCOMpare report HERE.
There is also a help page for cleaning the profiles you create from your GEDCOM HERE.
Please do not hesitate to come back to G2G to ask questions for anything you do not understand.