It’s similar to buying bitcoin in US. The market for bitcoin and other cryptocurrencies in Europe, specifically in UK which is still in Europe before brexit is not one of the most liquid ones. You can see the statistics on CryptoCompare. Well UK actively trades in Cryptocurrencies unlike any other countries in Europe. People in Germany are far more reluctant to buy any cryptocurrencies due to the time lag in adoption during the bull run of December 2017.
If you are more interested in marketplace you can go for BitBargain and Bittylicious, these platforms put you in touch with the local seller but only online or mobile payments are accepted. You can wait for CryptX Financial marketplace to launch in Europe to get access to edge of the art features for the marketplace.
You can always get cryptocurrencies from Bitcoin ATM near you which you can find in LocalBitcoins.