Campus Groups can approach external organizations for monetary or product sponsorship. Almost all sponsors will expect some form of return on their investment from your organization. In return for their contribution, you may consider advertising some of their products/services speaker or some other form of exposure. Remember that sponsorship is not always given in the form of money. In fact, most businesses are far more willing to offer sponsorship support in the form of goods and services.
Also note that as a club you are not a registered not-for-profit and can therefore not provide tax-receipts to organizations who sponsor your group.