Breakdown of wǒ gěi jǐngchá dǎdiànhuà.
Questions & Answers about wǒ gěi jǐngchá dǎdiànhuà.
Here 给 does not mean the main verb to give. It introduces the person receiving the action, so it works a lot like to in English.
In this sentence, the pattern is:
我 + 给 + 警察 + 打电话
= I + to the police + make a phone call
So 给警察打电话 means to call the police.
Yes, 打 often means hit, but in many common Chinese expressions it has extended meanings.
打电话 is a fixed expression meaning to make a phone call / to call. You should learn it as one common verb phrase, not by translating each character literally every time.
Some similar expressions are:
打字 = type
打车 = take a taxi / hail a taxi
So here 打电话 simply means call by phone.