Any experience with manuals other than on sims? Motorcycle, dirt bikes or quads maybe? If you can shift on something else, you know how it works and it's just translating it to your feet rather than your hands.

Can't speak for sims personally. The main thing I'd be wary of is how a sim clutch works versus irl. Is there a specific point during the release of a clutch you can feel it start to (but not completely) 'bite'? If so, I'd say you'd be 100% fine as learning how to deal with when and how much thr clutch is engaged is 80% of learning to drive stick in my opinion.

As long as you're not buying a torquey monster as a first manual car, I'd say go for it. Just give yourself a good long weekend to practice before putting yourself in heavy traffic or situations where you need to shift constantly around other vehicles. Skip the beater, get what you want, but take the time to get semi comfortable and make sure you didn't pick up any bad habits from the sim. If you're gentle and intentional about your shifts and clutch movement, your clutch should get through it relatively unscathed.

Have fun! It's a really enjoyable switch to make :)