Expat community boards

As much as I loathe it... Facebook.

Probably every country has expat forums on FB that will have information about how to immigrate. Every large city is going to have expat FB pages too, though it may not be all American. Here in Frankfurt we have at least 10 FB pages, some are just for women, some are for newcomers, some are for women in business, some are just foreigners and expats, some are specific themes, some may be military based, some may be offering stuff for sale, pet sitting, families with kids, travel groups, photography groups. Country pages may also be specific, like for British expats who want to immigrate, or for those from the US.
Just go on FB and search.

There are websites for most European countries. Which countries are you interested in?
Germany: https://www.toytowngermany.com/
Switzerland: https://www.englishforum.ch/

I am Irish by birth and Swiss by choice. I'm now retired (at 55) and have lived in Switzerland for over three decades. Back in the day I worked for a mix of US and Swiss multinationals. I am/was what the popular press would describe as a "Swiss Banker", although in Switzerland, bankers are people who are partners in a bank not directors of a bank, the difference being ownership.

Depending on the country Reddit also has boards for most countries.

Here's one of the Reddit expat subreddits - https://www.reddit.com/r/expat You could certainly ask some basic questions there, but if you are looking to emigrate to a certain country, you will probably want a forum that is specific to that country.

Calvados makes a good point—there are mostly-Brit expat forums/groups I follow for my target country, but, for my purposes, they are 90% noise. (Because of differing circumstances, demographics, concerns, motivators...)

We joined Americans Living in Italy FB group, which was invaluable before, during, and after we moved to Italy.

I've noticed a new kind of expat arriving now: people who have firmly decided to never return. They aren't in it just for the food, wine and architecture.