You need to replace the spaces
inside the string. so you do that with string.replace:
string originalString = "Pizza Cafe";
string minString = originalString.Replace(" ", "");
To add title casing, you can do this:
string originalString = "pizza cafe";
string minTitleString = System.Globalization.CultureInfo.CurrentCulture.TextInfo.ToTitleCase(originalString).Replace(" ", "");
Its long, but if you add a reference "using System.Globalization" at the top, it can be shortened to:
string minTitleString = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(originalString).Replace(" ", "");