I don’t think you can hope to get professional jobs in Spain unless you speak fluent Spanish, you find a post with an international company with an English-speaking culture, or you have a skill which is very, very valuable and rare. (For instance I know people who work in film-making in Spain who didn’t speak much when they arrived, but that’s a small and specialised industry.) You could get work, right enough, but it will be unskilled (and minimum wage in Spain is ?600 per month, which is not much). I know of Eastern Europeans (mostly Romanians and Slovaks, but some Poles) in Granada who have three jobs at one time - cleaning hotels, agricultural work and building labour.
Imagine what it would be like trying to get professional jobs in Australia without English….well the same applies in Spain without Spanish. (In some areas - including Valencia - there is a second local language to cope with too.) There are certainly people making good money who don’t speak Spanish, but they have built their own companies or develop and sell property etc., so you should consider those areas, maybe. On the bright side, as Poles you are already bilingual and so language learning is probably easy for you, relatively…. You could always come to the UK - as Poles you have a right to find work here and the Polish community is big and thriving. My local Polish bakery in Scotland is making lots of dough! (sorry…)
Incidentally, we knew a Polish family who bought a bar/restaurant in Malaga province. The young kids learned Spanish very quickly, but the parents found it much more difficult. There were comic scenes when the six year-old was taking orders for food and translating it into Polish for Mum and Dad at the bar. Sadly they went out of business in under a year.
