We unfortunately cannot give you an estimate on this.
Click through rates and conversions depend heavily on a number of things including:
1. The niche that you are in.
2. How well you can target this niche.
3. How well your message in your ad matches the desires/pains of this target audience.
4. How well you've setup your landing page (squeeze page for leads).
5. How good your offer is.
6. Which video ad format you're using.
7. How well experienced you are with paid advertising in general and how well you can optimise your campaigns
It can take some testing to find the sweet spot that will give you the highest ROI. Inside our course Video Advertising Made Easy you will find a lot of tips for each of the above mentioned areas.