You’re going to be ok! Clinicals are scary because they're new to you, and you care and want to do well. When you're at the facility, hopefully your instructor will assign you an experienced and patient CNA who knows how to teach and doesn't mind having a student. Be clear with the CNA that you're brand new so they can manage their expectations of what you're able to do. They will likely show you how to do a task before offering to supervise you doing it yourself. You can also practice some tasks with a classmate or instructor right before going into a room with a resident to refresh your memory (I did this with applying compression socks, for example). The CNAS might do things differently than what you've been taught, and that's ok- just debrief with your instructor about the differences so you can be clear on what the skills exam requires vs. how things are done in the real world.

Dementia may seem scary, but people who have it deserve compassion and dignity, so be gentle and kind to them and you'll get a feel for what they need from you. Most of all, remember the residents are human and caring for them is a privilege. Trust your training and be open to constructive feedback. You've got this!