Hi Akinjide,
1. On Upwork, you search and submit proposals to jobs that fit your skillset and expertise. In the 'Cover Letter', you can send a proposal to the client and let them know how you can help them with the project. You can also share some of your skills and experience that are relevant to their project. If your proposal is accepted, you will receive a message from your client and a message room will be created where you can continue negotiating with the client. If the client decides to hire you, they will be able to send you an offer as well.
2. There's a number of ways you can get paid. I suggest checking out this help article to learn more about all of them.
3. Yes, you can use the portfolio section on your profile. Your portfolio is where you have the opportunity to impress potential clients with real-life examples of your skills and expertise. Please note that for freelancers in the Design & Creative category, the first item in your portfolio will appear alongside your profile in search results. You can use your portfolio to show off projects related to any or all of your skills, so long as you personally have worked on every item you add and adhere to all of Upwork’s Terms of Service. To add one, go to your profile, scroll down until you reach the 'Portfolio' section, click on the '+' button and follow the steps.
As you are new to Upwork, I suggest that you take a look at this Community thread to help you get started along with the Freelancing Resources board in which you'll find plenty of articles to help you with writing proposals, negotiating with clients, setting your rates, enhancing your profile, and so on. On Upwork's Events & Webinars page, you can find official Upwork hosted events along with the ones hosted by Top Rated freelancers.
Thank you.
