All your questions can easily be answered if you:

1. Tells us your location (we need to confirm this is not in Astoria, Oregon)

and

2. Hire an architect local as per your answer in no.1 above.

 

I know it may seem odd, but real advice costs money. What you're asking for requires time and effort and no one will give you this for free.

Why do people keep asking for free advice on here?

Not paying for something is better than paying for it I suppose.

google cant seem to find anywhere with an average temp of 35C

you don't ask you don't get... cheepskate

^ good catch.

35C is a ridiculously high yearly average.

I don't really get bothered when people ask for free advice on a forum. I still look at car forums for technical help before going into a dealership for a lot of repair work or diagnosis. 

We are all here voluntarily looking for a distraction, so this sort of thing is entertaining to me. I'd be a lot more annoyed if I were actually dragged out to a build site during my own time only to give advice. Or even worse, asked to do up a sketch on the spot for free ( I've been asked for that ).  Considering this place is 35c all the time, I won't be making a site visit. 

That being said, when you are looking for free advice the quality will vary. As Non Sequitur says, real advice costs money. Free advice will be whatever some bored person wants to offer.

1. In terms of temperature, is a one-story building better or a two-story building for lower temperatures since I live in a place where the average temperature is around 35 Degrees Celsius .

Maybe.

2. How can I keep the building less hotter aside from having fans or using the A/C since I would like to have low Electricity bills as well?

That's going to take some work.

Is there a way to keep the inside of my house cool aside from having my windows open, Ceiling fan/Air Conditioner running?

Yes.

3.Is there a way that I could design my house to keep it cool all day long and at night as well since it is always summer here in my Country.

Yes.

4.Are there any kind of material that would help the insides of a house cool?

Yes.

5.Aside from having a roof to block the heat of the sun, is there a way for the heat being absorbed by the roof not spread inside the house?

Yes.

Landscaping, if large trees will grow in the OPs area, may be as important as messing with the house. Really need to know the area where the house is and its orientation on the site and the site characteristics first.

Easy answer, start digging. Dig deep enough and the earth will keep you cool and comfortable. No HVAC bills at all

Dont dig too far, cuz then its about 7000C

^ Give or take...

Have a look at the vernacular/traditional architecture in the area and use it for precedent/influence/research, many of your questions may well have already been answered.
 

Can I play too? 

1. In terms of temperature, is a one-story building better or a two-story building for lower temperatures since I live in a place where the average temperature is around 35 Degrees Celsius .

What's the floor to floor height?

2. How can I keep the building less hotter aside from having fans or using the A/C since I would like to have low Electricity bills as well?

Use something that doesn't require electricity to keep the electricity bill low. Have you considered getting ice delivered regularly?

Is there a way to keep the inside of my house cool aside from having my windows open, Ceiling fan/Air Conditioner running?

If it is 35 deg C outside, I'd recommend keeping the windows closed.

3.Is there a way that I could design my house to keep it cool all day long and at night as well since it is always summer here in my Country.

Of course there is, but it might depend on how much you want to pay for your electric bill. For a precedent, look at the indoor ski slope in Dubai. 

4.Are there any kind of material that would help the insides of a house cool?

Insulation comes to mind. But maybe ice would work too. Again, see that indoor ski slope in Dubai.

5.Aside from having a roof to block the heat of the sun, is there a way for the heat being absorbed by the roof not spread inside the house?

Insulation comes to mind. You could also try not having the roof absorb a lot of heat from the sun. I bet if you cover the roof with snow, that would help too; snow reflects a lot of solar radiation. 

Sam Sharpe, that is a very good answer. I hope the original poster takes it to heart.

Along with what Sam is saying, look at examples that predate mechanical cooling. Air conditioning has made us stupid as we've thrown out simple concepts of thermal mass, proper and effective shading and simple cross ventilation. 

You can also try old pop bottles below. Won't cost a thing. 

chris....I have a collection of those in my basement....but they are ocean spray cranberry plastic bottles....it is a winter project along with  developing a farting machine...