You will probably find that a lot of Americans will say "I have class now." They use it in the same way as "I have history now" - the name of the class. I had geography in the morning, I have history now, and I will have English at 4pm. I can't meet you at that time because I have class then. In British English we generally would use "a" before class, even though we would still say "I have history now." There is another meaning for "I have class." It means quality or sophistication, social status. That guy loves to fight, he has no class. It doesn't really matter. The important thing is that if you're asking questions of professional English teachers, you should use the English you already have learned. Sentences start with capital letters, questions contain a question word, and end with questions marks. What is the difference between ... ? Why do I waste my time teaching you things if you don't use them? Why do you waste your time learning things, if you're not going to use that knowledge? I know that grammar is hard and boring, and learning new words seems like more fun. But your English will not improve if you don't learn how the language works and start using it.

thanks a lot .

It is not proper to say "have class", it has to be " have classes" or "have a class" or "have the class"