Hey bud, I'll start off by saying that's quite the site. I haven't signed up, but the UI and design of the platform seems up to par with other competition. I'll write my thoughts and help you out below.
1. Where can I find vendors who can sell their products or service on our marketplace ?
Think back to how Ebay, Gumtree became popular marketplaces. This all goes down to marketing, running campaigns, influencer marketing, ads, SEO, etc. I'd recommend looking for a marketing agency that has experience with marketplaces, or in crypto. Constant updates, and building a loyal community with active support should be top priorities.
2. Which kind of websites we should partner with . Which should help both of us ?
No partners right now IMO. Focus on building an active marketplace before thinking long term.
3. Any other special crypto currencies you would like to see on our Marketplace ?
Just the top 50 on CMC is good.