Learners being able to upload a pdf

This is not possible using Storyline/Rise alone. This functionality requires some backend functionality as the PDF needs to be transferred and stored somewhere (on the server). You would need to determine if the server that you host your content on offers this service and if they do, ask for the instructions on how to implement it. There may also be 3rd party plugins that offer this solution, but are likely to incur a cost as they require server space and bandwidth to store any uploaded documents.