Greetings, welcome to the Forums. Your garden seems fine. It just need some grooming.
The grass may be Mexican feather grass (Nassella tenuissima). The dried leaves are considered a winter feature, but you can cut them back now. If not, do cut them back at the end of Winter as now blades will replace them in the Spring.
The reddish plants are red New Zealand Cabbage Trees (Cordyline australis 'Atropurpurea' or a similar cultivar). Just clean up the dead leaves. This needs to be done occasionally. You can remove them before they fall, but wait until they come off easily for the trunk.
The deciduous trees are a red-leaved cultivar of Japanese Maple (Acer palmatum cv.). Just rake up the fallen leaves. Of course, if the tree in the front has not had any leaves for awhile, then it might be dead. See if it re-sprouts in Spring.
Lavender (Lavandula sp. or cv.). It already looks nicely mounded for Winter. You can just leave it as it is, until Spring growth occurs.
That monocot seen in the foreground of the first shot, and again farther back, seems like an ornamental Sedge (Carex sp.) or something similar. Groom it as well as you can but a few brown-grey leaves are part of the look for such a plant, at least during Winter.
In Early Spring, give the whole bed a feeding with a complete fertilizer.
