Irrigation system with timer & smart control

You need to visit an irrigation outlet.

I know not where thou dost abide.

Just Google "Irrigation Outlet Store Shop" and your region/area. If you can't or don't want to DIY, they will be able to recommend someone well versed in the art.

It also sounds like you will need rain sensitive timers.

Visiting the Antelco website and looking at their catalogue and videos would be beneficial. You need to do your homework before making decisions.

You could also water the garden beds by using an electronic timer suited to a gravity fed drip irrigation system supplied directly (not pumped) from the RWT. This would substantially reduce costs. Don't use a pump to supply standard drip hoses when there is a low demand.

Also well prepare the lawn area's soil so it holds moisture to a good depth which will encourage deep root growth. The best grass to use will depend on your location and you can get deep rooted versions like the RTF tall fescue these days but again, the best choice for your situation depends on your area and lifestyle.