Working on a human character and when i try to add faces to attach the body it wouldn't work .. Tried F , Alt + F. Relatively new to blender.
I can see you have 2 objects, because there are 2 origins. First Join objects (cmd/ctrl + J). And yes, Joonas is right you have doubles (> Merge by distance).
Are they two separate objects or one? The meshes need to be one object before you can join faces. Once they are a single object, selecting the same number of parallel edges should allow you to fill the empty face. If that doesn't work, take a full-screen snapshot or possibly upload your file.
-
$\begingroup$ Try Looptools: W > Bridge. Select two edges you want to connect and use Looptools. $\endgroup$ – Jaco Sep 4 '20 at 7:36
You have overlapping vertices as can be seen from black dots with orange rods. Press A in Edit Mode to select all vertices and from Mesh drop down (or pop-up) menu select Clean Up > Merge by Distance.
You can also select vertices and press F3 and search Merge by Distance.
Next try filling again.