Your story resonates with me, as I see many similarities for myself.
I also decided Welsh was what I needed to be learning next after learning Spanish (though not as far afield as yourself, just over in Spain)
While I was living in Spain I volunteered with Workaway, which is similar to WWOOF, are you familiar? People place adverts for their ecological project, and in exchange offer accommodation and food, a fantastic way to cheaply experience the real culture of a country, while working with people with similar ethos and interests in small scale ecological farming and sustainable living.
I have checked the site for opportunities in Wales, which there are many, but unfortunately have not found any Welsh speaking ones, as often they are placed by anglophones, who although are often sensitive to the local culture, have moved in from other areas of the UK, where land is more affordable in Pembrokeshire and Carmarthen shire where a lot of this ecological farming and sustainable living.
Are you moving to the farm as part of volunteering or as a project of your own? This is an area that really interests me, as I have a lot of personal experience in the area.
I am originally from Tipi valley, a small commune near Llandeilio in Carmarthen shire. The place was set up in the seventies by a group that included my grandmother. As the name suggests people lived in tipis, and is actually what my mother, and then I was born in. Nowadays people also live there in yurts or traditional roundhouses, made of daub with turf roofs.
The community originally consisted of a lot of people from the new age travellers community, but there are now several generations who have grown up in the region, attending the local Ysgol Gymraeg. Living off the Earth is difficult but rewarding, and something that is still very important to me. Have you heard much about the community before?
I also know a lot of people who live in a similar manner in pembrokeshire
I too however had poor education in Welsh, as I was home schooled in Wales, then went to a school in Hereford. Finally after becoming quite proficient in Spanish I suddenly realised how important the language was to me, and an important part of my Welsh identity