There are 2 ways to mine cryptocurrencies. First is by setting up your mining rigs by buying the miners ( hardware). There is generally a waiting period for the mining hardware. Second is by buying could mining contacts from cloud mining companies.
Due to increased difficulty of mining and current market prices, you should first check whether such an endeavor would be profitable or not. You can check profitability on portals like coinwarz.
https://www.quora.com/How-we-can-start-crypto-mining-in-low-investment/answer/Kuldeep-Kaul-18