My two cents: make a landing page for each of these services, and run a LinkedIn campaign targetted for each.
Soon you will realise where is the demand. Why do the market research when a simple campaign can tell you how many clicks are coming for each service?
Check Click through ratio, cost per click, and contact form fill up. These things will guide you about what the market is demanding.
One more thing - start broad, and as you have enough work, start going narrow towards where your ability to serve and market demand both are highest. But in the start, try to take all kinds of projects. That will help you with the revenue.
All the best!
???