Hi , I suggest a mulch (? coconut fibre ) with a proper garden edge that you like . A landscaping supply company should be able to help you with both . I would remove the Bougainvillea as it tends to go wild and can be very , very painful .

We really need a bit more info on climate and orientation and your style preferences but to start with... pull up all the plants that are 30cm or below and pop them in pots for the time being. I agree with keeping the existing plants, they do have some appeal and to replace them with similar age plants is costly. Several of the plants are going well - so you could find out what these are and mass plants them. Then mulch and replant the smaller plants around the front of the garden bed.

I agree with bigreader, safely remove your little plants first, add new soil and compost, I would remove the yukka, they get huge and the trunk is almost impossible to remove as it grows , it looks like a tropical theme you have, look for large leafy plants to go beneath your palms, you really can’t overplant a tropical garden, the more lush the better, mulch, add a gorgeous water bowl ... beautiful

I agree, tropical foliage would be great. I think mulching and then paying some attention to the understory of plants would be a great idea. I have a tropical garden in my front yard, and a lot of the understory plants are subtropical ground covers that I have planted as cuttings. I collect tip prunings and a little piece here and there as I wander around the neighbourhood and then I plant them straight into the mulch and they take off. If they are thriving and escaping my neighbours yards then they'll be fine in mine. Concentrate of a small area and overplant almost with various creepers, they seem to enjoy the competition. when they are bigger you can take cuttings off your own plants and multiply throughout the garden. I have really enjoyed this type of garden as its quite fun to layer different textures and patterns of leaf. when the rain comes the garden grows so quickly! I have some purpled leafed plants, and stripey leafed creepers, and spikey shapes and velvety textures. I have then added into that 'quilt' of leafy creepers some bromeliads and patches of bulbs. the bulbs come up at different seasons and create interest. there are hippeastrums and day lilies and allums. I live in a subtropical region. my garden is only a year old and its looking nice now. You have all the feature plants, you just need to frame it!