How can we stop weeds from invading our garden

I have found the best way to do this is to pull all the weeds out by hand. Next take newspaper and put it down in very thick layers around your plants and anywhere else where Weeds might come up, then wet it well and lay your mulch down over top. I did this two years ago and have very little weeds coming up.

Build a greenhouse. You’re fighting wind and roots for spreading. Or, weed every day - gardening isn’t easy..

pull or smother them out with newspaper,cardbard,heavy landscape fabric and top with mulch

I have had great success with no till gardening. I used paper grocery bags and even cardboard as a weed barrier and then loaded it with straw. Check this out...https://www.no-dig-vegetablegarden.com/no-till-gardening.html