The term weed is used to describe a plant that humans don’t like. In essence, any plant can become a weed. Of course, weeds also has some other properties, for example, it is extremely good at growing anywhere. 
But it is important to understand that these plants are weeds only in our garden, but they can be a source of food, a source of medicine or serve functions we still don’t even know. For example, dandelion is an important source of food for bees in early spring. Some say that these flowers have the power to prevent cancer. I don’t know about cancer, but for sure dandelions have lots of vitamins. They young leaves can be added to your salad and it can be the perfect substitute for your rucola. 
Couch grass is another plant we tend to dislike. I understand your frustration when I try to say that there is something good in this plant. But I can’t help, but say that this grass has extremely good root system (that is why it is so good at invading your garden), so it helps to keep soil from eroding. It also provides shelter for insects and food for many animals. It also used to treat some diseases such as for example urinary tract or kidney disorders. 
I invite you to give these plants another chance this spring. Look at them as a part of your garden ecosystem. They might be annoying, but as your crops are important for you, these plants are imporant source of food for many animals.

Of course, we want to keep our gardens clean, but we can set aside a small spot in our garden to keep these plants alive. I left edges around my garden where these plants have a freedom to grow as they are pleased. We also can make a choice to not use any herbicide to get rid of them. April is the perfect month to weed them out easily. The plants are still very small and the soil is perfectly soft right now. If you take these plant out now, you will significantly decrease the amount of work you will need to invest later and have a garden free of herbicides.