It is not that bad. The words will not change their meanings and possibly in some cases you will be understood even better. If you are a novice language learner I suggest just to forget about vowel reduction. One example are the words **кампания** "campaign" and **компания** "company". With vowel reduction they are indistinguishable, so to be understood correctly you may in some cases pronounce the fist vowel without reduction. Another example is **маток** vs. **моток**