Your questions pretty much tell me that you have not managed to even log into said AP since AP configuration is usually more or less simple.
I am still 100% sure that quick start guide and manual would tell you that.
Besides that, no one of us can guess which type of AP you happen to have, thus no one of us can even try to give more specific examples.
To start with, where are you stuck?
have you managed to log into the AP using browser?
If not, read the manual
If not, plug the AP power adapter to wall
If not, read the manual again.
If not, plug the AP power adapter also to AP itself.
If not, read the manual.
If not, connect said AP directly, with a cable, to computer.
If not, read the manual
If not, set computer IP manually to same subnet as AP uses by default. (this is told in quick start guide/manual)
If not, read manual
or.. Try telling us exactly where you are stuck and with what type/brand AP you are using. For all we know, it could be something from -96 and it wont even support 802.11ac.
Still, if you happen to have same router/AP as I do..
log in
go to advanced menu
setup
wireless setup
Select channel name
select channel
select mode (pretty much channel width, my router tells max Mbps not Mhz)
transmit power control (to limit power and thus range, if you want)
select security options
done
All on same page.