Work out a budget for living expenses

You do realize that Brexit is happening don't you?

While you can currently move from Wales with no problem, there are some serious issues as to what your status would be in regards to several things after Brexit is finalized in 2 years.  So what are your longer term plans?  Are you actually thinking of staying in Spain and furthering a career there?

Tourism jobs in popular tourist areas like Malaga, pay about enough to survive on for a 'worker' and no more.  It is the same in all the tourist areas of Europe where tourism, 'workers' from other EU countries, are a dime a dozen.

As a summer job for a young person, they're fine.  The objective is not to get a 'real' job or start a career, it's just a way to try and pay for a summer living in a tourist area.

If you get a job working in a bar or restaurant and share a place to live with other workers, you would get by but that's all.  If you plan to then stay on for the winter, the 'off season', it gets more difficult.  All of this also assumes you can find a job.  Not everyone who shows up in these areas in say May does find a job before the funds that had when they got there, run out.