Dropshipping is the easiest to get into.. you can take items from Aliexpress.com and list them on Ebay at a marked up price (use US suppliers)
Get a t-shirt design made on Fiverr or Upwork for $5, put it on BigCartel using Printful and sell it to your family & friends on FB & IG
If you're a decent writer, you can produce content for mills like ContentGather or Crowd Content
Find suppliers with decent shipping times and sell wholesale products to businesses or individual customers. Gotta have some mouthpiece for this.
Sign up for Merch By Amazon.... merch.amazon.com. Requires approval. Takes a while but it's worth it.
You can simply sell items that you're not using anymore on Ebay, apps like OfferUp or Craigslist
You can eat off of being a middleman... I'm a wholesaler by trade so I'm always looking for unique suppliers. Decided to message this dude on Etsy who sells dope collectibles but had low sales. We talked and he told me that he lives in the Middle East, runs his own brick and mortar store but needed help selling online. I told him that I could help him. Long story short, I found an auction house on LiveAuctioneers.com that runs auctions every week. Explained the situation to them and they were like "cool." We set up a system where he sends me pictures of his items, the auction house lists them on LiveAuctioneers and if they sell he ships them to the customer from the Middle East. They take their cut, I take my cut and he gets his. I don't touch the merchandise at all and I don't market it either since they have their own built in audience. That's an extra $250-1000 every week easy.
Gotta be creative bro. Sit down for an hour with no distractions, brainstorm and think about different things you can do.