Looking for Advise-What to offer investors in exchange for Funds (other than equity)

Hi Community,
I'm looking into getting funding for my start-up (seed) and I have some people interest in investing, however, I'm not sure what to offer other than equity (common stock - preferred stock)
I'm not a financial expert and I need some ideas on what to offer, I heard about convertible notes and loans but if anyone could give share some ideas about it would be greatly appreciated.
Cheers,