When you open any English dictionary, you will find some kind of signs after the word, just before the meaning of the word, those signs are called Phonetics. Phonetics will help you, how to pronounce a particular word correctly. It gives the correct pronunciation of a word both in British and American English. Phonetics is based on sound.
Learning the basics of phonetics is very simple. The first or the second page of every dictionary will have an index of phonetics. If, you know to read them. That is more than enough to help pronounce any word correctly.
The index will show a sign, and against it you will have a word in which a letter or two of the word will be highlighted, which means the sound that comes on the letter when you pronounce the word, is the sound for that sign. You will have different signs for vowels, diphthongs and others. You just have to spend some time to get them right. Once you get an idea, then nobody can stop you.
Once you know to use phonetics, then you don't have to go behind anybody asking them to help you, to pronounce a particular word. You can do it yourself; you can even teach others and correct them when they do not pronounce a word correctly.
If you don't know to use phonetics, then what happens is, in case you don't know to pronounce a particular word, what you generally would do is look for teachers, parents or elders, whom you have the confidence would give you the correct pronunciation of the word. But, there are chances that the pronunciation given by them may not be always correct. And we start pronouncing the word that way, which is wrong.
And the worst part is, there can be youngsters and others who trust you, and have confidence in you, that you have a good command over English, and how ever you pronounce the word is correct. And just imagine if a later stage, they come to know that how you pronounced the word was totally wrong, they will not trust you anymore, even if you pronounce the word correctly. Which is the most embarrassing, situation one can face.