Hiya,
Perhaps my pre-covid experience in Barcelona, dealing with exactly these 2 issues, will be of help:
-Cannabis Clubs: I emailed 2 or 3 clubs before my visit, got a positive response from one of them: got to the Club, showed my ID (my non-European drivers license), registered my address (hotel) and paid an "annual membership fee" to gain access. I think the fee was 20 Euros, but I may be wrong. Once in the Club weed of various types was available for purchase. Prices as far as I recall were on par with Amsterdam.
-P4P: I used sexomercado (+Google translate), which has separate bulletin boards and forums for all major ES cities. I met 3 different ladies via the site, all Spanish, and they were all positive meetings. One especially I still list as a top 3 of all time for me.
https://www.sexomercadospain.com/valencia-f404.htmlHave Fun!
Mac