1.In the city food bar these kind of number appear like 23-24 or 24-23 what is that?
Food the city is producing - food the city is eating. This gives the food excess which is what causes growth.
Each population easts 2 food to survive.
3.Is religion important?I avoid religion so I dont get any negative relationship point from other religious leaders.
It gives a convenient source of 
and access to powerful civics (Organised Religion/ Pacifism) and can create solid alliances with AIs.
As you go up levels you will realise its important to make friends, and that you can't be friends with everyone. Its often best to make a choice to have your local civs like you.
4.Is it ok to chop down all the forest in your city radius to hurry production as there will be no health benefits and in future environmental civic will be useless.
The boost to forest preserves is actually the weakest part of Environmentalism, without forests you still gain the 
boosts and stronger windmills.
Also, its important to realise that later civics aren't always (or even often) better. Most of the time either Free Market or State Property will be much better choices than Environmentalism.
5.How to get benefits from corporation?Whenever I build their building my commerce goes to negative.
Corporations increase a cities maintenance costs by an amount proportional to the strength of the corp (number of resources you have) so losing some gold is normal. The amount you gain from the extra food/hamers or whatever should be enough to cancel the problem out.
Be sure to always found corporations in a city with Market, Grocer, Bank and the Wall Street National Wonder to offset costs.
Also, commerce and gold are not the same thing. Commerce cannot go negative.
6.At the start of the game what should I build first?warrior or worker or barrack or granary
Worker first while researching the techs you ned to improve nearby food resources (e.g. Animal Husbandry for Cows or Pigs) is best 9 times out of ten
7.Somewhere in this forum I read that wonders are not much important and only noobs fill there city with wonders,but I want to make as many wonders as possible,you cant avoid free tech,free promotion,etc.so main point build wonders or not?
Wonders are very expensive and many provide benefits that must be actively worked to get the most from, newer players regularly cause themselves huge amounts of damage by spending their hammers on wonders they aren't making use of.
The most notorious newbie trap wonder are The Pyramids, without Stone they cost a whopping 500 hammers, which is as much as 5 Settlers 
and new players almost never use them for Representation specialist spam..... which is the only reason to build them.
It would be best to learn the game without building lots of wonders so that you pick up all the basics for running your empire.
9.I play on no technology trading and no goody huts coz I think I can surpass Ai in technology and beside that no ai will come demanding for a tech,so does this option have more advantage or disadvantage?
No tech trading should make noble considerably easier than with it on, AIs rely heavily on trading with each other at all levels and on noble once your used to the basics you will be able to outpace the combined tech rate of the AIs without any trading yourself. Without the ability to trade the AI techrate on noble will flatline.
11.How far you should build your city?I used to build far for resources but now I just watch the working city radius and build near the capital but not crossing there working city radius tiles.
No specific distance. The first settler I build usually gets placed where it has a good resource in its inner ring allowing it to work it immediately.
Overlapping tiles between cities isn't a bad thing to do, just try to make sure each city has a food resource.
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