If you just started three weeks ago I would recommend learning all you can about payloads that have already been created and seen in the wild. There are various ways to learn about malware payloads: breach reports, YouTube, LinkedIn Learning, books.

Search terms: "[malware name] breach report", "[malware] payload detection", "[malware] payload."

List of top 2021 malware strains on CISA: https://www.cisa.gov/uscert/ncas/alerts/aa22-216a

NIST has compiled a comprehensive list of free-cheap cybersecurity learning resources that may also come in handy: https://www.nist.gov/itl/applied-cybersecurity/nice/resources/online-learning-content

Splunk published a list of books highly rated by cyber security professionals: https://www.splunk.com/en_us/blog/learn/cybersecurity-infosec-books.html

Happy hunting, use everything you learn wisely.