@juliana In the Netherlands, it's common practice to visit a local "kraakspreekuur" ("squatting office hours"), to get advice and support from existing squatters.

However, the practices and available support networks vary widely by country, also in part because of different legal protections (and non-protections) between countries.

So generally I'd recommend to ask the question specifically for a given country, or if at all possible, finding some local support group for it :)

This is particularly true because squatting is often a group activity, with different people responsible for different parts of the process to keep everybody safe.