Just an FYI, you never want to click on "ads" that claim to speed up your device. Whether it's your phone, pc, tablet or what have you. These are often spam ads, that could download malware, or get your email and flood your acct with spam, so just ignore them.
I assume you've had your Note 2 for at least a couple years? If you want to speed it up, connect it to your pc and back everything up via KIES. If you can't connect to KIES (older Galaxy devices were really hit or miss)
then just make sure your contacts are backed up to Google, transfer all your music, pictures, files etc to either your pc, ext sd card, usb OTG or cloud storage. Then do a factory data reset as Jeffrey mentioned. This will give you a fresh start. If you don't want to go that far, you could always download CCleaner from the Play Store and use it to clean all your cache files. A FDR would be the better option in this case, but CC should help a bit. Good luck and let us know how it goes.
S5 tap'n