How do I buy TLM coins?

Could you please provide me with a step-by-step guide on how to purchase TLM coins? As a newcomer to the world of cryptocurrency, I'm a bit overwhelmed with the various options and procedures. Could you explain the necessary prerequisites, such as setting up a cryptocurrency wallet? Also, where can I find a reliable exchange or platform to buy TLM coins? Are there any specific factors I should consider while choosing an exchange, such as security, transaction fees, or user reviews? Lastly, could you elaborate on the best practices for storing my TLM coins safely after purchase?