Its not hard to learn but it does take time to become confortable with it. I recommend renting a car. Driving manual car for the first time with the added stress of driving in a different county is a recipe for disaster. By all means try it. Take up the offer of that lesson, but its unwise to have to rely on a manual car for transport when you’ve never driven one before.

But also make sure you actually need a car. The US is built with fully car dependent infrastructure, so americans are taught their whole lives to just assume they always need a car. That isn’t the case everywhere, and might not be where you’re going. Be sure to check.