Uploading files in filezilla is just as straight forward as downloading files. You browse your computer on the left side of the screen and find the files that you wish to upload.
Then on the right hand side of the screen you navigate to the destination that you want the files to be uploaded at.
Then you select the files you want to upload, right click and click upload. You can also drag and drop the files from another window like explorer or finder, and drag them right into the right side of the filezilla screen.
If you have any questions, please let us know,