This is the 8834th most frequent Polish word.
spr
"Spr" is an abbreviation in Polish, often meaning "check," "matter," or "case," depending on the context.
Here, 'spróbuj' is a form of the verb 'spróbować' which means 'to try'.
Spróbuj to zrobić sam.
Try to do it yourself.
In this sentence, 'sprzedałem' is the past tense form of the verb 'sprzedać', which means 'to sell'.
Sprzedałem mój stary komputer.
I sold my old computer.
'Sprawdź' in this context means 'to check', deriving from the verb 'sprawdzić'.