Does doing an ordinary day-to-day job account for good karma? If you do an ordinary job, say anything like a software engineer, or a waiter in a hotel or a farmer, anything, like a 9-5 job. Helping society in whichever peaceful means possible. Does it accumulate good karma? I understand it is a 'Right Livelihood' but does it fill the storehouse of good karma?
I understand that 'karma' is dependent on the 'intention', but doing a job has no particular intention other than fulfilling your financial monthly obligations or getting the fodder for the fire to cook dinner.
Do we have to be in a position to help millions, like the Dalai Lama or Ajahn Brahma, or just an ordinary guy doing ordinary routine will also get one in higher realms?
Observing the five precepts, Right Action, Right Speech and Right Livelihood, i.e. virtues (sila), with heedfulness (appamāda), with the right intentions, certainly generates good karma.
In addition, accumulation of wealth as a layperson and use of this wealth in a generous, charitable way, is also good karma, generating merit.
Observance of the five precepts is also one of the prerequisites for stream entry. Please see this answer for details.
Of course, these are not sufficient for the permanent cessation of suffering. That requires renunciation. However, the path of the observing lay Buddhist may be able to lead one to stream entry.
From Ittha Sutta:

Long life, beauty, status, honor,
heaven, high birth:
To those who delight
in aspiring for these things
in great measure, continuously,
the wise praise heedfulness
in making merit.
The wise person, heedful,
acquires a two-fold welfare:
welfare in this life &amp;
welfare in the next.
By breaking through to his welfare
he's called prudent, wise.

The Adiya Sutta speaks about five benefits that can be obtained from wealth, and ends with:

'My wealth has been enjoyed,
my dependents supported,
protected from calamities by me.
I have given supreme offerings
&amp; performed the five oblations.
I have provided for the virtuous,
the restrained,
followers of the holy life.
For whatever aim a wise householder
would desire wealth,
that aim I have attained.
I have done what will not lead to future distress.'
When this is recollected by a mortal,
a person established in the Dhamma of the Noble Ones,
he is praised in this life
and, after death, rejoices in heaven.

From SN 3.19:

Like water
in a haunted place
that, without being imbibed,
dries up:
such is the wealth
acquired by a worthless person
who neither enjoys it himself
nor gives.
But one enlightened &amp; knowing,
on acquiring wealth,
enjoys it &amp; performs his duties.
He, a bull among men,
having supported his kin,
without blame
goes to the land of heaven.

And don't forget virtues once again, reminded by SN 3.20:

Grain, wealth, silver, gold,
or whatever other belongings you have;
slaves, servants, errand-runners,
&amp; any dependents:
you must go without taking
any of them;
you must leave
all of them
behind.
What you do
with body, speech, or mind:
that is yours;
taking
that you go;
that's
your follower,
like a shadow
that never leaves.
Thus you should do what is fine
as a stash for the next life.
Acts of merit
are the support for beings
in their after-death world.