What does the bible say about misunderstanding(s)? Particularly, trying to prevent them or what to do if they happened?
Misunderstandings happen. Because none of us communicate perfectly they will happen. Knowing that, God did provide some advice on reducing them, and especially on what to do when they do happen.
It may sound simplistic, but the Bible says the way to avoid misunderstandings is to love one another. "Be kindly affectioned one to another with brotherly love; in honour preferring one another." (Rom 12:10) I know that we have misunderstandings with out blood relatives-at least I certainly did with my brothers-but if we treat others as brothers, if we forgive them much and put their honor above ours, we will go far toward avoiding misunderstandings. If we "go the extra mile" (a phrase based on Matt 5:41) we will work harder at understanding. If we work more to understand that should reduce misunderstandings.
"Go not forth hastily to strive, lest thou know not what to do in the end thereof, when thy neighbour hath put thee to shame. Debate thy cause with thy neighbour himself; and discover not a secret to another: Lest he that heareth it put thee to shame, and thine infamy turn not away. A word fitly spoken is like apples of gold in pictures of silver." (Proverbs 25:8-11) Here Solomon says to talk it out privately so that there be no misunderstanding. Don't rush to misunderstand another.
When misunderstandings do happen, we are taught to deal with it as quickly as possible. The first passage I thought of was Matt 5:22-25, which says "But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire. Therefore if thou bring thy gift to the altar, and there rememberest that thy brother hath ought against thee; Leave there thy gift before the altar, and go thy way; first be reconciled to thy brother, and then come and offer thy gift. Agree with thine adversary quickly, whiles thou art in the way with him; lest at any time the adversary deliver thee to the judge, and the judge deliver thee to the officer, and thou be cast into prison." Not only are we to deal with misunderstandings quickly lest they escalate (v. 25), but we are even to interrupt our worship to God if we are aware that somebody has misunderstood us and work it out. We aren't to say, "It's his fault he misunderstood me." We are to correct it, even if we don't think we are at fault. But Matt 18:15 says that if we are at fault we should make the first move. That covers both bases. Whoever is at fault, it is our obligation to try to make it right as soon as possible.
There is, no doubt, much more said in the Bible about this. Particularly read the book of Proverbs which spends much time dealing with interpersonal relationships. I hope these few scriptures will give you a basic idea of what the Bible says about misunderstandings.
This individual asked another question related to this but because of the specifics in the question I was unable to post it without giving away personal information. The answer, however, was very similar to this.