I doubt that, as yet, Europe treats this matter in a holistic manner. As far as I’m aware, and there being still quite a share of confusion when I read on the matter, in Spain for example you would (in theory):

-   Consider the earned crypto as an equivalent to work related income, and it is subject to income tax, adding in global terms to the basis of what you earn through your regular job (if applicable).

-   Since the cost price is cero, it is considered to be an income equivalent to its market price at the time you received the income crypto TX (if you get paid weekly, each TX would therefore contribute at a likely different price rate).

-   You should keep as much evidence as possible in case of a tax inspection, bearing in mind that there is no written nor in any other way formal contract (i.e. keep info. on campaign payouts, google drive docs, forum related posts, and your TX history).

Tax office personnel is often rather clueless on this matter, which adds a fair share of doubt on the whole matter, getting potentially variable responses on the procedure to follow from one desk to the next.

Sales is a different matter, but will play on the difference in price between purchase and sale or swap, processing the sold amounts if a fifo manner.