Overclocking Help

[Fishcannon]

Hey everyone!
As of August 2018 I finally managed to get my first PC!!!!  Specs are as follows:

 

CPU: 
Intel core i7 8700k 3.7GHz CL 12MB
Motherboard:
MSI z370m Gaming Pro AC LGA1151-CL mATX
GPU:
MSI GeForce GTX1080ti Gaming X 11GB GDDR5X DVI 2xHDMI 2xDisplayport
Ram:
G.Skill 16GB (2x8GB) DDR4 Trident Z RGB 2400MHz
PSU:
eVGA SuperNOVA G1 + 650W Fully Modular 80PLUS Gold Power Supply
Cooling:
2x Thermaltake Riing Plus 3 pack 120mm RGB LED Premium Edition Fans w/ Controller
Cooler Master Hyper TX3 EVO CPU Cooler
Storage:
Samsung 970 EVO series 500GB M.2 NVMe SSD
WD Blue WD20EZRZ 3.5" 2TB 64MB 5400RPM
Monitor:
AOC AGON AG271QG 27" WQHD G-sync 165GHz 4MS IPS
Case:
Corsair Carbide Spec OMEGA Black Mid Tower Case w/Tempered Glass Side Panel
Keyboard:
Cooler Master MasterKeys MK750 RGB Mechanical Keyboard (MX red)
Mouse:
Corsair Scimitar Pro RGB Optical Gaming Mouse yellow
Headset:
Sennheiser PC 373D Surround Sound Gaming Headset

 

I have overclocked my GPU (WITH THE HELP FROM A FRIEND! as I really don't know what I am doing) but I really don't know if it is giving me much in the way extra performance (not expecting it to boost it by much). Could someone help me to understand the numbers side of things and also help me with overclocking my CPU? I would really like to get the best out of my rig! 

cheers  

[Wormhole]

watch a youtube video for overclocking your cpu, gamers nexus is probably the most reliable if he has one.