Follow reputable SEO blogs and news sites like Search Engine Land or Search Engine Journal.
Attend SEO conferences and webinars Websites like Search Engine Journal keeps on introducing conferences on different important topics.
Engage in online communities like Reddit & Twitter.
Follow Google's official blog and social media accounts.
Continuously monitor and analyze your website's performance
Read and learn with Google's Webmaster Central Blog, Moz's State of the Industry Report, Searchmetrics' Ranking Factors Study, and SEMrush's Sensor.
Connect with other SEO professionals on Youtube, Instagram, or Twitter.