I'd suggest that you start here:
https://bitcoin.org/en/faq#mining and maybe read the entire FAQ as it includes everything you need to know about Bitcoin in general in an easily comprehensible manner.
This page here:
https://www.bitcoinmining.com/getting-started/ is an up-to-date step-by-step guide on how to start mining Bitcoin. It includes some other resources that you should check out as well. It's also what the bitcoin.org FAQ suggests under the 'what do I need to start mining?' question.