hello
m new in vb.net so would anyone can help in
how to comparing the input of the textbox with respect to the given text and the number of error in typed textbox?

How accurate do you need it to be? You could break both strings into their separate elements and then match each one but that may not be very useful. If the user puts in an extra space but everything after that is OK, the match would report everything after the extra space as an error.
You could break each string at the space character and then match the characters of each word - then errors don't persist onto the next word...