It's not possible to walk anywhere from the airport. It's built on a manmade island. Do you have access to Google maps? You can look up these locations as well as transportation options. You can also search for nearby hotels. So here we can see, for example, that it takes about an hour to get from the airport to Osaka and the train fare is about Y1200.
View attachment 119687
Did the university tell you the location of the hotel they are suggesting? There are many options but here's a cheap hotel within walking distance from Osaka station.
【Official】HOTEL LANDMARK UMEDA