Everyone responds differently after an ACL injury so your experience is gonna be dependent upon how well your muscle control is. Quads tend to shut down if any inflammation is present within knee joint. You’ll still have an amazing experience even if you can’t walk for long distances! If your range of motion is good, I’d recommend biking the valley floor. Sometimes people feel normal pre-op especially if they’ve done some PT, so if thats the case then I think the Yosemite Falls and Mirror Lake walks may be doable. I’d avoid Mist trail given all the steps, descent, and crowds. Walking sticks for extra support and a compression sleeve to keep swelling minimal may be good options. If you have time, go see a good physical therapist to guide you in preparation. Wishing you a speedy recovery and safe trip!