Of course we would love if you learn Polish language! If you decide not to, you can still try to speak other languages. At least basic level of English can be expected with younger people. Some people speak German, especially in near-border regions. Other languages like French, Italian, Spanish are of secondary popularity. Russian was a mandatory foreign language in schools for a long time, so many older people are still able to speak it.
From time to time you will be forced to spell Polish words. To help Poles understand you, try to avoid most common spelling errors: