You need to choose whether you want to be a front-end developer or back-end developer, or maybe you want to build applications for iOS, Android, etc.
Very useful article: https://hackernoon.com/learn-to-code-in-5-months-get-hired-and-thrive-as-a-web-developer-5ab6838b2f07
The easiest course on web development: https://www.udemy.com/result-oriented-web-developer-course/
2. To become a back-end developer, you need to learn one of the server-side programming languages such as Python, PHP, C#, etc.
For example, a good course on Python https://www.udemy.com/complete-python-bootcamp/
3. To become an iOS developer, you need to learn Swift or Objective-C. Apple launched its own programming language (Swift) in 2014.
Very useful article: https://lifehacker.com/i-want-to-write-ios-apps-where-do-i-start-1644802175?fbclid=IwAR2iBH6W-Ooyp_nKcY40gnhR-ocIYVC8QFWEaI0MJuIiztlc1LTMk6_r4rU
4. To become an Android developer, you need to learn Java. Please notice that both Java developers and Android developers use the Java programming language, but there is a big difference between these two.
Useful article: https://www.itcareerfinder.com/brain-food/blog/entry/how-to-become-an-android-application-developer.html?fbclid=IwAR3VNRF6owN0rLt3dDM0izZZCn232qbwlDyMeXTUe32QD8ONniifcyTPLhY