Working out your target market is the extra step required after doing your broader industry research. You will need to address the following questions:
Is there an urgency to people wanting your products or services?
How big is that target market? If you are unsure of your target market, it might mean you need to further clarify your products and services. An business/marketing advisor can help with this.
How much are they paying for your products or services?
do you know how much it will cost you to obtain a customer. this will vary radically based on the type of products / services you are selling. eg. if you are selling some business software to a large business, you cost of sales would be much higher than if you were selling a coffee in a cafe.
The more specific you become, the clearer your marketing messages will be and you have a much better understanding of the amount of money you need to commence and continue your business.
Does your products or services need development. How long will it take you to get to market? Your target market could change if it take years to bring your products and service to market.
Along the lines above, you need to know if you target market will still be around, so does your product / services have a roadmap - you will need to determine future plans.
In the industry you are targeting, there may be opportunities to bring new products or services to market that might not yet be met by your target market. If you find some hidden opportunities.
Learn as much as you can about the existing competitors in your target market and what their offerings are, how they promote themselves and how happy their customers are (google ratings).
Try to figure out what you are missing before commencing your business, this will increase your likelihood of success with speed and less cost.