Welcome to Embrace Shabbat.
The משנה עוקצין states: לא מצא הקדוש ברוך הוא כלי מחזיק ברכה לישראל אלא השלום, G-d did not find a vessel to hold blessing for the Jewish people other than peace. The Chidah explains this to mean that even if a person has his own personal merits and the merits of his forefathers, and even if G-d was already planning on bestowing blessings upon him, the blessings will not come to fruition unless the individual has peace. Peace is that vessel that holds life.
If Shabbat is the mekor haBeracha, the source of all blessings, the only way to receive that blessing is with Shalom. It is for this reason that even before Shabbat begins, a person must work to bring Shalom into their life. The Gemara teaches that if a person only has enough money for wine for Kiddush on Friday night or for Shabbat candles, he should purchase the candles. Bringing light into one's home is the priority, as it increases Shalom Bayit.
Without peace, the blessings that come with Shabbat will not be fulfilled. Shabbat begins with the lighting of Shabbat candles to bring Shalom in with the holiness of the day. Additionally, the Amida concludes with the bracha of Sim Shalom because a person can request healing, parnassah, the Beit HaMikdash, and anything else, but without Shalom, the brachot will not materialize. We must work on getting along with others in order for the bracha of Shabbat to come down. A person can have everything, the Chidah says, but אם אין שלום אין כלום, if there is no Shalom, there is nothing.
The Malbim extrapolates that the first step to everything is ואתה שלום, a person must be at peace with themselves. Their emotions, desires, and wants must be put to rest, because if a person does not have inner peace, they cannot have peace with people or in other areas of their life.
We start our Shabbat with ואתה שלום. Find inner peace and calmness. Realize that HaKadosh Baruch Hu is taking care of your life. Go into Shabbat in a peaceful state and when you have ואתה שלום, then you וביתך שלום will follow, and in the end you will have וכל אשר לך שלום, and then blessings can come down.
Shabbat Shalom.

