it is very simple. yeast is all around us in the air. You just have to mix whole grain wheat flour with some lukewarm water, to reach the consistency of a gravy. You put that in a water glass and cover loosely with small plate or something, air has to circulate. You let that sit on your kitchen counter, covered loosely with kitchen towel, for 1 day, or 2 days (depends how warm it is in your house). Yeast forms from itself and it SHOULD smell strange and become bubbly, nothing wrong with that, it's yeast growing.
Then you take whole grain wheat flour, put this starter in it (cca glass of starter on 500-700 g of flour). Kneed with some water for 10 minutes, and form a ball of dough. Then cover it and put it somewhere where there is no draft. I put it in cold oven. After few hours, the dough will rise. You kneed it once agin very very gently. Then you put loaf in a pot that you have warmed up in the oven first. Before baking it in the oven, put a lid (without plastic parts!) to completely cover the pot, so the bread can rise and rise in all that humid atmosphere, before the crust forms. After 30 minutes or so, take of the lid and let the crust form.
I KNOW it sounds complicated, and believe me, you have to fail like ten times, before you figure out the right proportions and procedure. To me, bread making is a spiritual thing, and it happened very often that it turned out bad when I was in a bad mood. So, you have to be in the mood and believe in your baking power
SIMPLE WAY, without starter is:
Make dough a out of whole grain wheat flour and lukewarm water. Put it in warm place without draft to sit one day, or two. It will rise from itself and become smelly. Kneed it gently once again and put it in warm pot and bake as described above.
ALSO, if you decide to bake every other day, save a peace of dough, and use it as a starter for the next bread. That's how village people here do.