Starting a coaching business is fewer steps than it feels like from the outside, and most of the overwhelm comes from trying to do everything at once instead of in order.
Here is a straightforward sequence to work through, roughly in the order each step actually depends on the one before it.
A recognised certification is table stakes, but it does not define your business on its own. Decide who you actually want to coach and what makes your approach different, before you spend money on anything else.
A single, well-defined package is easier to sell and easier to deliver well than five options built before you have taken on a single client. Expand once the first offering is actually working.
Decide on one-time or recurring pricing, connect a way to actually take payment, and make sure a client can go from interested to paid in as few steps as possible. Every extra step between the two loses you clients.
Your public page, your intake process, your pricing, all of it improves with real client feedback far faster than it would from more planning in isolation. Launch earlier than feels comfortable, then adjust.