No, you would browse and download files via your Windows 10 computer browser (chrome, Firefox, etc).
In FileZilla, for host, port, UN and PWD you would enter the deails for the color classic. Once connected you can send files from your Windows 10 computer to the Color Classic.
Edited to add: in FileZilla you will usually have 4 panes: status log, transfer log, local directory, remote directory.
To transfer a file, navigate the local directory pane to wherever the files downloaded on your Windows 10 box. Once connected to the Color Classic, you should see it's hard drive contents in the remote connection pane. Navigate where you want to drop the files. Then justness drag and drop files from local pane to remote pane. The progress should show in the transfer log pane (as well as some info in the status pane).
Additional note: this works two ways, you can also drag files from the Color Classic back to the Windows 10 box wifh FileZilla (and any other ftp client, usually).
Additional Edit: in NetPresents (I think I have 4.1 as well), once you start the server it usually pops up a window listing the log of that current session. In there you should see your IP, and port number. Maybe your user name as well.