Put a lowball offer on a small office building garage but have no down payment.

I looked at this property almost to humor myself and get motivated to save and purchase to expand my business. Well they kept on me about making an offer so I put a low offer in and they accepted (15% off asking price) now I’m looking for financing. I can afford the building but as of now I have about 5-8k in cash. I do have a personal HELOC I can draw from but I’m looking for some advice on where to go from here. Thanks