For example you can start a drop shipping or an Amazon FBA Business. If you like e-commerce this is a good option to consider. With drop shipping you won't have to worry about any inventory and can focus on marketing and customer support. A great way to get more into it is to follow the blog on shopfiy.com . You can also buy and take over already running Shopify stores. So you just have to find a niche, your vendors and design your shop. If you want a private brand, some vendors support private branding. So you can send them the design and they will ship the product with your brand design on it. Amazon FBA works pretty much similar except you don't have your own online shop and have to send your product to Amazon upfront. Amazon FBA ONLY works with private branding so you won't have the possibility to earn money with well known products here. Anyways: You should be able to stay within your 5k budget with both options! So it may be worth a shot.
Best of luck and kind regards.
Best regards. And good luck!