That will list everything and hopefully provide a brief description. You can also do some Googling here. Disabling services that come with windows generally won't help performance much though. If you install services yourself (or install programs and install services) that take up a lot of RAM, then that could make a difference. If your RAM usage isn't constantly high, you should be OK.
Double click on a service and stop it if you wish. If you only want it to be started when it is needed, then click Manual in the dropdown box as opposed to automatic. I wouldn't mess with these things too much.
when I bring up "windows task manager" I see some that are not listed "BCMSMMSG.exe" and others. Also see some running twice?? this all may be for nothing the not knowing is what buggs me
There are some that should be running more than once like svchost.exe or rundll32.exe. There will be ample information on legit Windows services on Google, so it won't be hard to tell which you should keep and which you shouldn't.