1)Need proper כוונה for the first פסוק of קריאת שמע, you must go back and repeat it, as it is מעכב to your חיוב of קריאת שמע.🔂🙇♂️
2) What is “proper כוונה”? The שולחן ערוך explains
When you say the words “שמע ישראל”, you should have in mind that you’re announcing to כלל ישראל and that they should listen to what you’re about to say.
When you say יקוק, you have to have in mind not just its pronunciation, but the way it’s spelled and what the letters represent
ה׳ היה הווה ויהיה״” - Hashem will be, Hashem is, and Hashem was.
When you say אלקנו, You should have in mind that ה׳ is in control of everything and can do anything
When you say יקוק, you have the same כוונה as the first time.
And when you say אחד, you have to have in mind that ה׳ is the one and only real existence ☝️1️⃣
