Always go for the peaceful in life.  It helps keep the soul calm.

if a person is new to meditation (suppose that he hasnt tried mantras not much), if that guy is just an average person/ person with negative mental thought pattern. then if he does meditation there is a good chance that he can think negative while in meditation too which will cuase things worse. MANTRAS come to rescue here, each mantra has a particular vibration which attracts energy to a particular GOD/ DEITY or to particular subject like there are mantras for gettting knowledge/ attracting money / attracting spirits ........ list goes on.  Only thing is that a person should be aware what does mantra he uses is intented for & how to properly chant that else meaning & vibration of mantra changes which can attract many negativities

When you find your own true inner peace - even among the clamour of negativity - you can rest (meditate) with any mantra or other tool and it be successful.

gayatri mantra is one of the most reverred in HINDU & BUDDHIST culture

AUM BHOOR BHUWAH SWAHA,
TAT SAVITUR VARENYAM
BHARGO DEVASAYA DHEEMAHI
DHIYO YO NAHA PRACHODAYAT

single word by word meaning
AUM:primordial sound,the Godhead, Supreme Deity|Bhoor: earth or physical plane|Bhuvah: water or mental/astral plane. Swaha: fire or celestial plane |tat - that (referring to God)|savitur:the all-pervading Consciousness|vareNyaM - most excellent, fit to be worshipped| bhargo -  splendor (the light that bestows understanding)|devasya - divine, of the deity|dhîmahi -  we meditate upon| dhiyo - prayer, intuition, understanding of Reality |yo - he who, the one who|nah - our, of us|
prachodayât - may he energize, direct, inspire, guide, unfold... or he who energizes, directs, inspires, guides, unfolds

Complete meaning
We meditate on the glory of the Creator;
Who has created the Universe;
Who is worthy of Worship;
Who is the embodiment of Knowledge and Light;
Who is the remover of all Sin and Ignorance;
May He enlighten our Intellect.

this mantra is one of the best for gaining knowledge, because we all have come to the world for learning & finally GOD is knowledge and love (only thru true knowledge can anyone show unconditional love towards anything)

Medition is not a term I know .  Meditation is the blessing of quieted thought
and tendency of mind to begin passive thought pattern as restful to mindful.

When a mantra is blessed upon a person who will meditate . , . they begin a
cycle of recognising thoughts as quiet and not the jumble of mind which is ~
the stress of unorganized mind at rest . Mantra helps the mind trained to it :
with peaceful slowing of the theta and mindful centering of the mentality . . .

When mantra is not the recognised "sweet spot" in recognising quieted thots ,
it becomes the role of the "mantara" [new spelling] to begin Anew meditation.

Not having blessing of monk or teacher to begin the recognition to quieted and
peaceful mind to enjoy the inner peace with meditation will not be efficient . . .
Closing the eyes and beginning with peace and centered mind will help with the
role of mindful beginning of mantra , and when trying newer mantara it will be :
recommended to not focus the breathing pattern at time of newer recognise 0M
mantara will be the way to remind the unbothered mind about less thought aum     comment accepted .|.  OM  Evard .