Syed, the most important step towards launching any product is market validation. You need to talk to potential customers of your products. To as many as possible. Entrepreneurs who miss that step and end up building products that miss the mark.
Depending on what the product is, if you are not a domain expert in that field, then you should surround yourself with people who are experts. This could mean hiring an expert in that field as an executive.
In a startup environment, particularly if you are bootstrapping, there are no clear role demarkations. You need people who are willing to roll up their sleeves and get stuff done. Sometimes it is talking to customers, pitching to potential investors, brain storming on marketing strategy, or even testing the code.
Instead, if you are a VC funded company, then the VCs may force you to bring in an external CEO if they think you are not experienced enough.
Your question is too hard to answer without knowing the specifics of your situation.