I am typing a document on I pad. I wan to type the title on a bolder size. How do I do that

You will need to provide the name of the App you are using for this. How you bold text or increase font size is entirely dependent on the app in question.

Pages? Word? Notes? Some other App?

Which App are you using to create your document? Would this be Apple’s Pages App, Notes, Microsoft Word - or something else?