Evergreen Brushes Advise Please :)

Hi All,
I have absolutely no knowledge of gardening, I would really appreciate some advise of someone in the know
I would like some advise on the best evergreen brush options for a south facing front garden (well not quite a garden, just a small patch). When I say evergreen, i really mean some hardy bushes that will keep strong through the cold winter months and don't require much maintance. The area is very sunny during the morning, but the large tree does provide shade. I would like some bushes hat are fairly fast growing and when established I would ideally like them to be 0.5 meters (or over) high, as I would like them to provide some privacy.
I have added some pictures of the area, I intend on planting the bushes next to the wall for privacy.
Ideally I would prefer a mixture of different brushes/plants. I would like ones that either don't flower or flower white/purple/blue. I sound very fussy, but I have a colour scheme planned for my front
In front of the evergreens, I wanted to plant a few smaller plants. I have been told lavender is a good option?
The area was covered in grass and weeds, I have started to pulled them all out and turned over the soil. However I am worried they will appear as fast as I managed to get rid of them. Can anyone recommend a weed killer? which will not damage the existing tree? also would weed membrane help?
Also sorry to add another thing, I would like the plants to be doggy and child safe.
Thanks so so much for your advise! Have a great day
Olivia