I've read a lot of posts and comments on this forum in the past few days but I saw few posts or replies saying "this have been talked about many times before " ,as a fresh forum user like me how will I know if something like that have been discussed before?
Reading.
Keep making minor research for yourself and learn from already asked questions; don't coke out to ask yours except it's explicitly-detailed repetition, with a different point of consideration, - such that Haven't been discussed or shared before.
If you'd sacrifice time to read, you'd realize that we have search engines and you should prolly Know how that works right?!
Also is it wrong for someone else to discuss what a person have talked about before?
Yes, it is wrong. We have a term for that; it's called plagiarism. Simply copying, spinning, inter-changing words in a fact that's not your ORIGINAL idea( where ever you got 'em doesn't matter to anyone). If you must copy and paste, then don't fail to add a source link. Peeps have paid with their accounts for their ignorance in their newbie days, Beware!
Sandra 💇