How do I start a liquidation marketplace business?

Two sided marketplaces are a very common type of MVP to build. Using no code (shopify, wordpress, bubble) can get you some traction and gets you some amount of painted doors (someone knocks on the door, but it's not real, at least you know how many people knocked).

This can work for a month or two, but it is not technically defensible, and if your idea succeeds, most of this work will have to be discarded. You want to validate cheaply, but you can do this with a MVP that is hyper focused.

Check out some more of my thoughts on no code platforms:
https://mvpengineer.com/no-code-platforms-worth-it/

and minimizing your MVP:
https://mvpengineer.com/building-tech-demos-for-micro-components-not-a-full-user-experience/

1- Start with a small capital to understand the market
2- Find your customers' needs
3- Shopify is an excellent website for sale and it is very easy for you, but you must know how to work on it
4- Choose a main product and the rest of the products are additional and expand into the main product, for example (clothing).
5- Make a small profit margin and rely on expanding the customer base

Rather than shopify, you can use wordpress as you will have control over full source code:
- Go to http://wordpress.org/ and download the WordPress Marketplace plugin.
- Install the plugin and activate it.
- Click on "Add New" in the marketplace menu and input the following details:
- Name: Your marketplace name
- Category: Mobile apps
- Subcategory: Apps
- Upload a .zip file of your app.
- Click on "Create My Store Now!"

If you know shopify, then yes. Use whatever can get you there fastest to present something to your first users. Once you build the traction you're after, look towards setting up a better tech solution that serves user needs with a clean user experience.

B2B marketplaces are inherently different, but not more complex to market. To start, you might look into buying some of that inventory yourself or doing things manually for a bit to evaluate demand.