Hi Jessica and Chantelle,
Those are great questions, specially in a time that dropshipping is so hot. I'd like to introduce you to a more fresh platform called Spocket: https://spocket.co/
Spocket is offering wide range of products from suppliers around the world, focusing on suppliers in US/Europe. Products are high quality and ready to sell. Shipping is very fast for products on Spocket and the entire process is automated as well.
Spocket is FREE to start with and you can find it on Shopify app store:
Let me know if you have other questions.
I have a suggestion that you can also have a look at Dropshipmate shopify app where you can find a list of Supplier sites like Amazon, Ebay, Walmart, Dhgate,Aliexpress,Alibaba and 15+ etc and you can set your own price rules according to your price margins. You can find your niche products brand/Unbrand and can import easily into your shopify store. By the way, you can also enable auto-sync update feature which helps to update your store products automatically. It also provides semi-automated order fulfillment which helps you to place order easily with a single click.
All the Best...