You may or may not get Homegroups working on Win 10, as sometimes they break due to a 'phantom' legacy Homegroup that stops you creating a new one. You can try file sharing without Homegroups by following the instructions below. This worked for me.
For sharing to work without a HomeGroup, all libraries and folders on all computers which are to be shared need to have Read/Write permission set on them for the identity 'Everyone'. This is set by right clicking on the library or folder and going to Properties > Sharing.
1) Then on each computer use REGEDIT to create a new DWORD value called 'AllowInsecureGuestAuth' in HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters. Set this new value to 1.
2) Go to Control Panel > Network and Sharing Center > Change advanced sharing options. Expand the 'All Networks' section and go to 'Password Protected Sharing'. Turn off password protected sharing as shown below.
3) Reboot the computer.
4) Do this on each computer.
Sharing should work fine.