How to improve a MacBooks running speed

[yumzone]

Macbook 2016 - running 11.01 slur

Hi can anybody help me speed up my MacBook?
It was running fine before the software update

Things are running slow and not opening - seeing a lot of the rainbow coloured thinking circle?

Any advice would be gratefully received ?
Many thanks

 

[Furka]

Do you have an SSD HD ?