Should I invest a clean energy mutual fund? If so which one is the best to invest?

I am a small investor who only invests a few thousand dollars in the stock market at a time (1-5 thousand dollars).

I started with $500 in san disk when I was only 9 years old. I waited a few years and then used the money I made on that to invest in a different company. A few years later I put my money in tesla; then, four years ago I put my money in Nvidia. Between the time I bought San disk and now I have taken out some money here and there, so I currently only have around $8,000 in Nvidia. Thats it.

Recently, I was thinking about taking half or all my money out of Nvidia and putting it into a different stock, or a mutual fund. I think that green energy will inevitably overtake gas and oil and experience tremendous growth within the next decade or two. I was wondering if there are any good green energy type mutual funds, if it is a good time to invest in this type of mutual fund, and if so what specific green energy mutual fund should I invest in. Again, I am only looking invest 2-4 thousand. Let me know what you guys think. I would greatly appreciate any advice. Btw, if you guys think it is safe and more advantagous to simply stick with Nvidia, then please let me know, but I would think that green energy stocks would be skyrocketing in the next few years. Maybe, should I even invest in rare earth metals?
Thanks.