So I putted the "luckperms" plugin in the folder but the plugins seems to not work?

lp
lp
lp
lp
lpb
[15:03:27 INFO]: Unknown command. Type "/help" for help.
luckperms user RareDragon set luckperms.* true

I tried to access "lp" but it doesn't work?

I need to see your full log file

[15:02:04] [Server thread/INFO]: [LuckPerms] Enabling LuckPerms v4.0.80
[15:02:04] [Server thread/ERROR]: [LuckPerms] ----------------------------------------------------------------------
[15:02:04] [Server thread/ERROR]: [LuckPerms] Your server version is not compatible with this build of LuckPerms. :(
[15:02:04] [Server thread/ERROR]: [LuckPerms]
[15:02:04] [Server thread/ERROR]: [LuckPerms] If your server is running 1.8, please update to 1.8.8 or higher.
[15:02:04] [Server thread/ERROR]: [LuckPerms] If your server is running 1.7.10, please download the Bukkit-Legacy version of LuckPerms from here:
[15:02:04] [Server thread/ERROR]: [LuckPerms] ==> https://ci.lucko.me/job/LuckPerms/
[15:02:04] [Server thread/ERROR]: [LuckPerms] ----------------------------------------------------------------------

Wait? It needs to be 1.8.8?

Yes, there is absolutely no reason to use 1.8.
Do as the message says.