My first Wikipedia edit was on July 7, 2003, and I began editing in earnest in April, 2006. I reached my 10,000th edit in February, 2014, and my 15,000th in April, 2017. One of my biggest Wikipedia activities is posting new articles, on subjects I either know about or am interested in; I've posted over 400 of them. Another is reworking weak articles that I happen to encounter and take an interest in. I also add information where it's needed and where I can help, and I fix errors wherever I encounter them. I used to watch a handful of controversial articles, mostly to help make them better, but also to see how well/poorly the editors deal with them. It wasn't pretty, so I stopped.
I've started many new articles about U.S. Navy ships and aircraft squadrons. I've also started a significant number on the Navy, ships and shipbuilding, the works of C. G. Jung, and cowboy songs, as well as other topics that happened to interest me. One of the rewards of starting articles is seeing how other editors expand and improve on them.
WARNING: The paragraphs below plainly state the qualifications and accomplishments of an experienced person with many interests. If you consider such material immodest, you shouldn't read further. In any event, remember: If it's true, it isn't bragging.