As an NES but not an English teacher:
One suggeion that I might make is to use the KISS principle, particularly in informal writing.
As an example, I would say "Hi!" rather than "Greetings, everyone." and:
I'm an .... engineering student ... from New Delhi. As you may gather, I'm new to the forum and not yet used to the rules"
"I aim to achieve a 'native level' of English speech. My problem is - how to achieve it"......
Basically, I try to:
Never to use long words when short ones will do.
Use as few words as possible - "student" is fine - most NES' s know New Delhi is in India.
Unfortunately, I often break my own rules by, as they say, using long sentences "because I don't have time to write short ones"!
Hopefully this should start you off.
Try rewriting your text, on your own, cutting out unnecessary padding, using shorter words, where possible and see if it meets your own expectations of NES style.
Oh, PS: I've not been native for around 20 years now!
Apologies to the teachers if I've broken any grammar rules.