Try to take something useful from this example at https://answershark.com/writing/formal-presentations-and-speeches/acceptance/receiving-a-twenty-year-service-awar.html. I know that it's difficult to prepare a speech and presentation, but it's important to concisely explain the essence of your dissertation, offer solutions to problems. With fonts, you just have to experiment, since I don't know which room will be. Prepare your speech in advance and tell it to someone several times so that you don't have any stops and awkward moments.