I don't see anything that is obviously bermuda. The dormant grass in the first picture might have bermuda in it. Here's what I think I see in the second picture.

Nutsedge is a sedge which looks like grass. Common name is nutgrass, but grass killers are harmless to it. You would need a sedge killer like Sedgehammer or one of the Image products. Nutsedge is a swamp loving plant that usually goes away when you water deeply and infrequently and comes back when you get a couple days of rain.

Kikuyu is an aggressive plant with thick stolons. The blades are pointed at the end. St Augustine has blunt tips on the blades.

If you want to have a nice St Augustine lawn, you would want to kill all of this first. Kikuyu is aggressive enough to coexist with St Augustine and leave it looking weedy. It might be aggressive enough to take over the St Aug.

Thank you again for your reply. I have a patch of another type of grass if you could please help identify whether I should keep or not before installing sod.

That patch is St Augustine. You can see the difference with the blunt tips on the blades. St Augustine spreads, obviously, but in a much more forgiving way than kikuyu. Kikuyu is a turf grass in Asia and Australia, so they have found ways to deal with it. I suspect it is much more of a pest in certain environments than others. Sort of like how the Brazilian pepper tree is an invasive pest in the Gulf marshes but an expensive specimen plant in SoCal. Anyway if you can get rid of the kikuyu, the St Augustine will spread and take over the rest of the yard. It spreads about 15 feet per year in all directions. The following year it will become much more dense within that 15-ft expansion zone and spread another 15 feet. That's how I let my lawn fill in over the past 6 years. St Augustine will even coexist with nutsedge when you water deeply and infrequently. About 20 years ago the city dug up the water pipe leading to the meter at my house. They replaced the soil with bermuda and nutgrass crap. I never worried once about that. By the end of the growing season it was all St Augustine again. Here are before and (almost) after pix of my back yard.

Hopefully you can tell which is before and which is after. Before was prairie weeds (I live in the country) and bermuda. The only St Augustine is the slightly green edge of the back patio where the table is and also the far side where it is green up against the foundation. I never added any sod or seed to what you see there. And I did it while complying with the water restrictions.

In your recent picture, is that is a citrus tree next to the brick wall? If so the brick wall will break as the tree expands. Citrus needs to be in the middle of a yard or at least 15 feet away from any structures.

Sorry I overlooked and missed your reply. Yes those are my lemon and tangerine trees that have been here before I moved in 10 years ago. My next concern is whether the St Augustine grass will do any harm to the tree or I should put an edging board between them.

I got most of my weeds out and getting my sprinklers fixed in the next couple of weeks. Also deciding to minimize the grassy area with some sort of sand material that I have seen (Attached photo). I try to find out the material in the Internet and only found something call polymeric sand. If anyone knows anything about the material used in the photo or have a better suggestion.

I appreciate you taking the time again to answer my post. Have a great weekend.