Hi, I have 2 young boys under 5. I'm ngl, Shabbos can be long and challenging with little kids, especially in the summer when the day is longer. I find that if I'm prepared for Shabbat with good toys and treats for the kids, it helps a lot.
A successful Shabbat is about being present and spending time with the important people in your life, kids/family/friends and connecting to God.
Shabbat begins on Friday at sunset and lasts until Saturday nighttime, roughly 25 hours in total. In the winter Shabbat begins as early as 3:30pm. Friday night I light designated Shabbat candles to welcome in Shabbat, and my husband goes to Shul to pray for about an hour. I'll usually sit on the couch with the kids and read books/play with kids/pray. Once DH comes home he'll sing some traditional Shabbat songs/prayers including a beautiful prayer called "Women of Valour".
We'll then begin the Friday night dinner meal. Ours is usually very kids centred and we'll chat to them about school and talk about biblical stories on the Parsha, sing Jewish themed songs. Occasionally we have guests at our meal, and often we get invited out to join family/friends at theirs. Then bedtime, Hurray.
Shabbat morning usually begins a little later, (because of kids its 7am instead of 6am🙃) DH goes to pray 9am - 11am, Kids usually play nicely for a bit and then I give them some Shabbat party (nash), kids will play outside weather permitting. We'll begin the Shabbos lunch meal at around 12:00pm. The rest of the afternoon DH and myself officially take turns resting and babysitting, but kindly, most times my DH offers to do all the babysitting here. We'll often go out to visit family or in the summer, go to the park. Later, there is a tea time meal which is usually light consisting of Challah, dips, salad. DH goes to pray for another hour or so, and then Shabbos is out.
Shabbat meals start with a Shabbat blessing whilst holding a cup of grape juice, then we wash our hands before cutting into the Challah. We begin and end all meals with a blessing thanking God for the food.
My Shabbat treat is buying myself a good book to read and just having time to pray which I often struggle with during the week. My favourite part of Shabbat are the long Friday nights, kids are sleeping by 8 and then DH and I have hours to read and just cozy on the couch (no TV/devices). Also, I love the Shabbos socialising, I'll usually visit my parents on Shabbat day and sit around with my siblings chatting for hours, whilst the kids play with their cousins.