The best option, as @Caleb Heimsoth mentioned, is probably to "house hack" by living there. There are FHA loans available that only require 3.5% down. You would be required to live there for at least a year.
If living there is not an option for you, you can attempt to negotiate a carryback from the seller. Essentially, you would ask them to loan you a portion of the down payment which would be secured by a second position mortgage.
Third, you can try to raise money for a down payment from private lenders. This would be the same idea as a seller carryback, except that you would actually be raising money instead of simply asking the seller to accept a deferred payment in exchange for interest.
Finally, you can try to find a partner. This can be a good option (especially if the other option is not investing at all), but I think that you should consider it as a last resort unless you are also getting something other than money (i.e. someone with a lot of experience who can teach you). If all you are getting from a partner is money, giving up equity is less appealing to me if there are other good options.