I want to find an authentic translation source of Manusmriti(where I can not only learn the outer meanings but also the inner ones) Can I find it anywhere?
You can find it here
Word of warning, Manu speaks in very ambiguous terms, so don't take his words at face value. Also, while the Manusmṛiti is mentioned a lot in cannon scripture, it is never truly endorsed (not including unendorsed quotes that contain a bunch of other, problematic stuff)
Here Dr Surendra (he was head of department of sanskrit at MDU,rohtak) critically examined every verse of Manusmriti and explained which verses are interpolated . Though it is your opinion whether Manusmriti is interpolated or not and whether reasons provided by author for interpolation are right or wrong but good thing is that Dr Surendra 's translation is quite apt even of those verses which he called interpolated.