Login in to Magento Admin.
Go to Marketing -> Catalog Price Rule From Navigation
Add New Rule from Catalog Price Rules Magento Admin page.
Fill out below *Requierd fields of cart price rules
Rule Name: Enter your Rule name Like Monsoon Sale , Summer sale etc
Websites: If stores have multiple website than select specific website.
Customer Group: Select Group who can get benefit this rules.
You can write condition and Configure Action for Catalog price rule.
After that Save and apply Catalog Price Rule and re-index your site.
finally , on Front-end catalog product price rule applied.