Digital Marketing consists of many important components like SEO (Search Engine Optimization), SEM (Search Engine Marketing) / PPC (Pay Per Click), SMM (Social Media Marketing), Email Marketing, Inbound Marketing, etc. These acts as powerful pillars of digital marketing.
So, Mastering these main pillars or components will make you succeed as a good digital marketer. Don't worry you can learn and achieve by yourself using the internet as a weapon. I mean that you can get everything about digital marketing (from A to Z) on the internet, but it's possible only with much effort and dedication. This process of learning yourself can take little longer time compared to when you joined any institutions.
Coming to Digital Marketing online courses or certifications by Google - Google has a dedicated academic platform known as "exceed LMS" where it provides many certification courses focusing more on SEM concepts completely for free!! [you can just type "exceed LMS" in google and click on https://www.exceedlms.com/]
In this course, you can get certified in the following areas of digital marketing:
1. Google Ads Fundamentals
2. Google Ads Search Certification
3. Google Ads Display Certification
4. Google Shopping Certification
5. Google Ads Video Certification
6. Google Ads Mobile Certification
7. Google Analytics
8. Google My Business
And many other courses
After completing these and applying them practically, you can become good at running SEM/PPC campaigns and can become Search engine marketer.
Google also provides a basic introduction to digital marketing course known as "Google Digital Unlocked Course". You can search the name on google.
You can learn how to run ads, campaigns, and many things about Facebook marketing through "Facebook Blueprint" a course by facebook.
My good suggestion for anyone starting digital marketing is stay updated with market trends and try to learn as much as possible (don't stop learning/improving, even you become expert in this field) since this market keeps changing very frequently. Be ready for that if you are entering into digital marketing and willing to succeed.
"I can confidently say that the only constant thing in Digital Marketing (mainly SEO) is CHANGE"