We all gotta start somewhere, right? The most common struggle I hear from new VAs is that they just don't have any experience or feedback yet, while for most cases, that's simply not true. You likely had a job before or helped out a friend or family member with something that can be related to the services you wanna offer now. And you shouldn't downplay them, just because they weren't on a freelance basis or maybe because they were unpaid.
If you've never worked on Upwork, you won't have the feedback on your page from previous clients; that's a given. And while I wouldn't recommend you work at $5/hour for your first year or even month (unless that's a fair rate for you), I don't think there's nothing wrong in offering a discounted rate for your first 1-2 clients, as a way to build up your profile. I would be 100% transparent with the client and let them know this pricing you're offering is a one-time thing, just to help build your profile, but I would still let them know of any relevant past experience.
Something else you can do while you don't have any clients on the platform, and this is another recent add on by Upwork, is to ask for testimonials from people outside the platform. There's a section on your profile where you can do this; you simply need that person's name, LinkedIn, and email to be able to send the request.
You can send this request to past employers if you have a good relationship with them, beta clients that you've worked with (including those friends and family we mentioned before), or anyone that can attest to your skills – a coworker, for example.
This feedback will be showing in your profile, along with that person's name and title. So when a potential client lands on your profile, they'll see that you have people that can vouch for you and your skills, and they'll be that more likely to trust you and want to hire you.
Again, we all gotta start somewhere, and this is the easiest way to add some credibility to your profile while you don't have much going on yet.