Unfortunately the only way to change instance is to make a new account there.
For example, sopuli.xyz is relatively large, uncontroversial, and well maintained. https://join-lemmy.org/ has a list of all(?) instances and a thing that lets you filter them by topic and language.
When a Guardian reporter pointed out on social media that the image was not a genuine photograph of the generally small and tame protests outside the Immigration and Customs Enforcement field office in Portland, the Oregon Republican Party’s X account replied: “We’re not reporters, just bad memers.”
Schrödinger's lie: it's to be taken at face value, but if you catch it, then it's just a meme bro.
Really, just keep doing random projects and look up things along the way. Other learning resources like courses can help too, but should be considered supplemental.
when would be good to start a new language after learning one
Do you feel like it? If you're interested in some language, just try it.
I used it some years ago. It "just worked," but later when I tried to install it again, it didn't. I probably could've made it work again, but I didn't actually need it badly enough to bother.
He'll be back.