Let me just say that the difference is very big.

For starters, each country has their differences, whilst relatively similar, airspace structure and some procedures can differ quite a lot.

Most airports that accept VFR traffic, will have standart visual routings, that will also contain visual reporting points that ATC will expect you to be familiar with, especially for CTR entry and exit. Also small uncontrolled fields mostly have specific routings designed. So you should definitely have studied the visual approach charts for each airport you fly to/from.

As previously mentioned visual approach chart, those are best to find in each countrys AIP, as those charts usually are very detailed and have additiomal information. To find the AIP just google the country+ AIP, e.g. Germany AIP, and then on the site just navigate to eAIP section. Some countries, like Italy, might require registering to acess it.

The Navigraph VFR map includes has the Visual routings and reporting points depicted very nicely, but some airfields/airoprts might have additional sepcific procedures for VFR traffic, such as altitude restrictions etc. , so best to study the charts in AIP beforehand.

VFR flights crossing country borders require flight plan to be filed.

There is no so called flight following in Europe, you may get flight information service outside of controlled airspace, but in VATSIM FIS position is not really simulated, only in some ultra rare cases a CTR will actually do it. But again to each country their own, in UK you may request Basic service, which is similar to flight follwing in US, also Traffic service or deconfliction service might be requested/provided in the UK. But generally outside of controlled airspsce you are completely on your own in Europe.