How do I buy THETA stock?

I'm curious about the process of purchasing THETA stock. Could you guide me through the steps? I'm new to investing in cryptocurrencies and would appreciate a clear explanation. What platform should I use to buy THETA? Do I need to set up a wallet first? Are there any fees associated with the purchase? And once I have the THETA, how do I keep track of its value and potential gains? I'd like to understand the entire process from start to finish to ensure I make a wise investment decision.