@Belassi, Didn’t want to scare you (just inform you). Kloe is completely right and I find the people, including in companies and universities very kind and helpfully whichever language you communicate with them in.
Only situation I find difficult (other than my awful accent) can be coffee breaks where people try to talk in a language you all understand, but can’t help but revert back to their native language from time-to time which is understandable.
Regarding, Wales, when I lived in Cardiff there certainly were nighclubs that were Welsh only, and that was in a predominantly English speaking part of the country!