I think you're going to have some familiarity with Livewire to accomplish this.
If you're still fairly new to Laravel in general, I would recommend first trying this on a brand new project. Just have a basic form with a button that allows you to upload a file. Setup all the database fields as needed.
Once you have that working, move onto Livewire. There's an entire series here on Laracasts with an episode dedicated to file uploads: https://laracasts.com/series/livewire-basics/episodes/11.
Once you're familiar with Livewire, you should be able to integrate it into Jetstream.
You can also see how Jetstream implements it in these files:
/vendor/laravel/jetstream/stubs/livewire/resources/views/profile/update-profile-information-form.blade.php
and
/vendor/laravel/jetstream/src/Http/Livewire/UpdateProfileInformationForm.php
Good luck!