Your question isn’t silly at all!
If you book a trial lesson, it depends on the teacher’s style, but generally, you can absolutely ask about English and learn during the session. Many teachers use trial lessons to understand your goals, assess your level, and introduce their teaching methods. Some may include small talk at the beginning to get to know you, but you can definitely ask grammar questions, discuss pronunciation, or request help with specific topics.
If you have a particular focus in mind, it’s a great idea to mention it when booking the lesson so the teacher can prepare accordingly