Keyword research is the most important strategy before starting SEO for your website. You should have to know before which keywords will give you long term benefits through Google. There are free tool available to find the most valuable keywords, named Google keyword planner Tool. You can find the similar keywords with search volumes and get idea for better keyword targeting. Keyword planner will show you the long list of related keywords for your business. You can make a keywords list for target in your website.
Types of keywords
Long tail keywords
Location wise keywords
Which type of keywords we should target on website?
If you are physically located business and provides local services then you should target location wise keywords. These types of keywords are very helpful to derive traffic to your website. You may be training institute, clinic, saloon, transportation and logistics services, etc. For the new domains we suggests first for long tail keywords with and without location wise keywords.
If you offer online services then you can target generic keywords (short keywords). Like online shoes, mobile online, paytm coupons, etc.