How do I know the minimum amount required to open a trade of Shares CFD? / Axi

How do I know the minimum amount required to open a trade of Shares CFD?

This concept can be better illustrated with the following example.

Example: 100 shares of Walt Disney shares at a price of 175.

Formula: Number of Shares* Share Price* Margin Percentage

Calculation: 100*175*20%= USD 3,500

Additional Information

Why am I not seeing any Shares CFDs on my demo account? Will I be entitled to dividends? Do I have to pay tax for dividend? What is the minimum trade size to open a trade of Shares CFDs?