I am not sure if there are any activities readily available in UiPath Go that can help you in converting PDF files to word. If not available, you would have to create a new custom activity using C#.
See the link below for possible activities on UiPath Go that might help you.
https://go.uipath.com/components?sort=most_relevant&search=pdf%20to%20word
If they do not work for you, see the link below for a webinar on creating custom activities.
ashokkarale
Anil_G
Yoichi
yangyq10
postwick
chandreshsinh.jadeja
aravindbalineni123
Parvathy
aya
PRASHANT_GABHANE