Hi Maya and welcome to the forum,
Just to give you a better understanding of the Lab, it generates results directly from eBay itself which show where the market currently is on certain products. So it's actually a very good tool to give you some ideas on products. Once you find a product you think is worth further looking into, then you can search the directory to see if we have any suppliers that have it currently available and get further into the research on it.
The term "most lucrative, less competitive" is an oxymoron in this industry in most cases. Any product that has good margin will usually be saturated with sellers, making it extremely competitive and virtually impossible for smaller, less cashed up sellers to find any sort of success.
The markets where smaller sellers will usually find more opportunities are the less lucrative markets. By the term "less lucrative" I mean either less margin or much slower turnover time markets. These markets are usually ignored by much of the competition, at least the big cashed up sellers anyway because of those two factors,
Cashed up sellers look to invest in high turnover markets typically. It's not all about the margin with many of them because a high turnover market can delivery mass smaller margins quickly.
Where to start, well if you can start in a market that you are passionate about, then great. Of course, that's not always possible for various market factors that may be playing against you, but that's a good avenue to at least research to see if there are in fact any possibilities there for you to get kicked off and rolling.
Many people start off by selling off some odds and ends from around the house and you would be surprised at how many find markets through doing that and then that gives them a focus to drive forward. It's impossible to suggest a possible product, what may be a good selling item today might drop off the radar due to changing market dynamics tomorrow.
It really comes down to research and a lot of test marketing to hone in on a good product/s and even after you've done all the research to find that/those, then you have to continue to research to ensure you stay ahead of the market to build long-term success.