Lets see. First go ahead and go to the start menu and in the search box type "cmd" without the quotes and hit enter. You should now have a black window. In this window you are going to type "tracert www.google.com" as a test. Let the ping do its thing, this will probably take a few minutes. The latency of all the stops combined should be between 10-200ms depending on your ISP. Don't worry about '*'s that show up, those are stops that don't have their echo enabled. I don't know which servers you play on in CS:GO, their IPs should be listed there on the menu. As for finding the IPs for RL follow this guide
http://www.psyonix.com/forums/viewtopic.php?f=34&t=24962 If you notice your tracert gives a high ping at the top of this list is going to be closer and possibly on your end. Somewhere in the middle but still close to the top of the list will be the ISP's problem. Further down the list will be the servers that form the infrastructure of the internet. Near the bottom will be the servers that the game uses.
Any questions?
Moving on to routers.
Do you have an android device? If so grab this app,
https://play.google.com/store/apps/details?id=com.vrem.wifianalyzer
This will scan the area around you for wifi signals and give you graphs. Generally it will show you which channels are most congested and give you suggestions for alternative channels. I'm not going to go into detail on changing what channels your router operates on. If you don't have android you can skip what's above (or find a friend with an android device).
To find if your router supports 5ghz just look up the model number specifications online. Should be printed on the back or bottom of the router.