Solid advice in the replies there! My summarized 2c: Don't be delulu. The cranks are often mentally ill, (Especially narcisism), and aren't able to hold their ideas and observations in a consistent reality. Avoid that, and you're cleared hot to be an amateur, and explore fields you're not credentialed in.

Take the scientific method and mindset to heart. Be skeptical. Humble. Your own fiercest critic. What unites the cranks isn't being amateurs; it's screwing up the above.