Cornwall is a lovely place, if a times spoilt by my fellow countrymen who invade Cornwall during our school holidays and who buy second homes there (which distorts the property market). The Cornish people, well those who haven’t retired to Cornwall, are generally quite poor. IIRC then, relative to the U.K. norm, only a small proportion of people in Cornwall are well paid; some of the Cornish even choose to weekly commute (they work a hundred plus miles away in the week, in better paying jobs, and return to their family at the weekend) - well that’s my recollection of how things once were.
The coast and cliffs can be lovely but there is much to see and to enjoy in-land too. I used to have relatives in Cornwall ... but people die and others have to relocate to where work is available; occasionally I still holiday there but always outside of the UK State School holiday dates.
We must look to the future, but with this Covid horror I fear that a visit in the late Summer and Autumn of 2021 will be the very earliest date that you can hope for - assuming that international travel is allowed and free moving then. Cornish weather is usually nice so time there in September and October might well be very pleasant. Hopefully the Uke Clubs will be meeting again by then and if I remember correctly Cornwall has several of them, perhaps something for you to check out in advance and if you chose to visit any of them then I feel sure that you’d be made welcome. We might have left the EU but, in my estimation at least, people in the U.K. are (still) very welcoming to our European neighbours.