Intro level classes or beginner classes are specifically designed for someone with no previous experience. Sometimes trial offers are available and can be a good way to try before you commit to a longer course.
No. Beginner courses are designed for people with no prior strength or flexibility training. You will build both gradually by simply showing up to class. Everyone progresses at their own pace, the key is consistency.
Wear something comfortable that you can move in, like a T-shirt or vest and shorts. Leggings are okay if they can be rolled up, as classes progress we will need more bare skin on legs and under arms for grip on the pole for safety reasons.
That's completely normal. Everyone progresses differently, and breaks are part of the process. Go at your own pace and let your instructor know if something is too much.
Modern studio poles are rated far beyond human bodyweight (often hundreds of kg when properly installed) including the forces generated during spinning and climbing. Beginner classes stay well within these limits.
It is never too late to start exercising, pole is for everybody. Many studios will have an 18+ policy due to instructor training and insurance requirements for working with younger ages. Check with your pole studio on their policy.