basic knowledge
Computer foundation includes computer composition, counting and coding, software and hardware foundation, etc. This knowledge can buy a book on computer basics.
Applied skills
Application skills are gradually accumulated. I suggest you read more magazines, soak in forums (such as in-depth technical forums) and communicate with friends!
training class
For the training class, it is unnecessary if you don't want to take the certificate or learn more professional computer knowledge. General training courses are more professional, and they all learn professional knowledge such as C language, data structure and database, so I suggest you lay a good foundation before considering whether to participate in training courses!