You clearly haven't done any research on visas.
The UK Gov website has links for each country if you enter search terms of the countries you are interested in and 'foreign travel advice'.
If their Civil Service operates like the UK, it will only be open to those with citizenship or who have lived legally in the country for multiple years.
Your law degree is likely to be completely irrelevant.
Admission requirements - Switzerland
UK nationals coming to Switzerland to work from 1 January 2021 are subject to the admission requirements in the Foreign Nationals and Integration Act (FNIA). This means that from 1 January 2021 only essential managers and specialists from the UK will be admitted to work here provided this is in Switzerland’s overall economic interest. Persons with specialist professional knowledge or skills may be admitted if it can be shown that these skills are required. Swiss residents and EU/EFTA nationals are given preference, and the wage and work conditions standard for the location, profession or sector must be observed.
There are multiple visas offered by Australia (often with the emphasis on specialist skills/areas of shortage) but you are unlikely to be able to waft in to any country with a sum that is half the annual income there.
You don't say what your current job is. If you can do a legal job remotely (or any remote job paying the equivalent of 30,000 euros salary) in the UK and your employer gives you permission to work overseas , you could get a Digital Nomad visa for some countries in the EU and some other International destinations.