Further details at https://onetreeplanted.org/
You do not need to follow the Elon Musk example
any much smaller number will be fine as well :-)
As alternative you can think about using https://www.ecosia.org/ regularly or even as your new standard search engine, to plant trees automatically. Can it be easier?
"A tree you pass by every day is just a tree. If you are to closely examine what a tree has and the life a tree has, even the smallest thing can withstand a curiosity, and you can examine whole worlds." -- William Shatner, Canadian - Actor Born: March 22, 1931, https://articlebio.com/william-shatner