focus on only one target or try at least a few?

Because of the nature of startups, they have multiple ways of proceeding with the product. this is the problem right now for us.

we were planning to for go for global but now we noticed there is a need for local service also. or it can vice versa.

Although the topics can be consider as same, up to a level, the user experience and usage will be of course different. we can easy try to fork the code and tune the application to proper products but this will cost a lot for us. on the other hand productizing them in one service may(not always but sometimes) not be the best experience for user.

you can consider this a bit like : chasing to be twitter and facebook at the same time

is it risky to try both? would you consider it as a distraction ?

You say that the usage of the product will be different between local and international users. Do you understand how and why it will be different? Can you find a common ground that serves both types from a single product, and does it well?

If you don't have the knowledge, get it.

If you've got this knowledge and you can find a common ground, and can ensure the product works well for everyone, that might be the way to go if you want global exposure - but understand that global takes much more effort, for much longer, with much less chance of success - but with the possibility of a much bigger payout.

If you can't find a common enough ground, or don't have enough time, take the local product and go for it with everything you have. If you wish, you can always look to diversify later, once you have cashflow.

Pick the one you can excel at and focus on that one first. You really don't want to be distracted on multiple things since that will dampen your ability to get stuff done.

With that said, think of your specific application as a platform (Stack Exchange) is a good example. Build your application with that in mind but don't loose site of your main focus.

I know it sounds contradictory but it's really not. You want laser focus on a specific product that will generate revenue and then once that's done, you can think about the next produce or enhancement.