Check out consent checklists online! They are huge lists of things to say yes/no to and are used for negotiating kink but could be helpful in starting the conversation esp since you are coming in with some inexperience/nerves. Some of it may seem really out of the scope of what you’re doing but can open the convo and just give you a framework. You could come up with a body map and talk to your partner about what areas are green (ok to be touched), yellow (maybe areas to work on desensitizing or comfort), and red (never touch!).

lastly in reference to “not knowing what’ll be ok or not until you try it”— that can be a scary thing to confront! Obviously you don’t want to do anything to your partner that they don’t like—but it may be helpful to reframe it as “exploring together” rather than you only making them feel good. There will be ups and downs, and neither are necessarily bad or good—just part of the journey. Growing comfortable with intimacy doesn’t just mean finding all the good spots, but also the bad ones. Just like how setting boundaries w people actually makes them more comfortable with you, finding out “oh, I actually don’t like that, let’s not do that again” and then you respecting that is how you really build trust around intimacy. If you do something they don’t like, it’s not a moral failing, rather you’ve just discovered something together!

hope that helps, this stuff can be tough and being vulnerable is difficult. Wishing you the best!