1. Agree on the frame before you touch
Three separate things, said out loud before anything physical. First, direction: is this leading to sex or not tonight? Saying "I'm not planning for this to go anywhere" is your commitment — not a lock on her wishes. If she changes her mind later, that's hers to say; if she doesn't, that's the design working, not a failure. Agreeing on "nowhere" is a common choice for a first session — but it's one option, not the correct answer.
Second, range: is internal touch on the menu tonight, or outside only? "Not leading to sex" and "no internal touch" are different agreements — name both. Third, the reporting: agree that you'll ask about pressure with a 1–5 scale and that she can move your hand or speak up at any point.
If saying any of this out loud feels awkward — that's common, not a sign the two of you are bad at this. A lead-in like "this isn't rejection, I want to touch you without it having to go anywhere" helps. And if words fail entirely, starting with hand signals and working up to words is a legitimate path, not a lesser one.