I think the best investment tool is education, Invest in yourself, learn, there is a lot of information and tools you can use if you know what are you doing. The best is most of the information is available free of charge, don't follow gurus that sells you courses, follow your own path.
Even if the free one is the best, but its harder to be understood, buying a course is not a wrong move if you do it well. Just make sure the course is affordable to buy so you wouldnt regret it later. The another one that i would preferred to be invested is a land, since the supply is limitted meanwhile the population keep grows.