"How to find my potential customers".... the questions is like how far is a tread as we say in Sweden.
Option with sales consultant is you want to have some goals and groups to target so they can be more effective. A good sales consultant should also be able to find some relevant sources too.
Option without sales consultant.
How much work are you willing to put in ?
I would start with reverse engineering.
Look at current companies in similar area on e.g. LinkedIn and see which companies and people they interact with this will give you initial clues.
Depends on which segment and level of companies you want to reach out to. I would say just be bold and dare to contact the larger firms also. Focus on building relationships not only selling since some of them might not be interested in the long run but they might consider you in the future.
E.g. do you want to be a premium level provider or a midrange or cheaper and have more volume on customers?
Got to start somewhere right, but don't get stuck on the wrong end if you want to be a premium level.
Google tools and relevant communities for SaaS and Startup companies might be go. If you're able to do few gigs for references.
Let me know if you want to follow up there are so many options it's just based on which options you consider more fun so you can enough during your journey.