Most home kitchens do not need a block of twelve. They need three blades that cover the week: a chef’s knife, a petty, and a bread knife.
The chef’s knife does the onions, the chicken, the herbs. Eight inches is the length most hands learn fastest. Start with one you will actually pick up — Victorinox if the budget is tight, MAC if you cook every night.
The petty (or a sharp paring knife) is for the work a chef’s knife bullies: garlic cloves, strawberries, the tomato on the side of the board.
The bread knife is the only serrated blade worth owning. It stops you sawing a crust with a fine edge you then have to sharpen.