The word order in the second pair of sentences is more natural. The 'get' version sounds particularly awkward in the first pair. There is no difference in meaning between 'gain experience' and 'get experience', but 'get' is more informal. When I was a child at school, I had an English teacher who forbade us to use the word 'get'. 'Get', she said, was an ugly little word and a lazy shortcut, because 'get' can (nearly) always be replaced by a better word. In conversation, it's fine to say 'get experience'. But if you're writing a CV, job application or personal statement, it is better to use 'gain'. This goes for any formal written text - if at all possible, use a more specific verb than 'get'. Acquire, obtain... anything but 'get'.

Hello Hamed Your re-phrasing of the sentences is correct. Thank you Umang

"Gain" is a synonym of "get", however "get" has many meanings that are not so similar to "gain". The word get has too many meanings, so I would use another word when possible. Like gain, in this case. Also I prefer your second form "The more mistakes you make, the more experience you gain". Because it puts the focus on the action and the consequence, not "you the person listening". When your sentence uses "you" to mean "whoever hears the sentence", not "a specific person or group", then the focus should not be on "you". Contrast that with the sentence "you made a mistake", which is targeted to a specific person.