I want to start a new scientific journal. After doing all he initial work about setting up a journal now I want to know how will I be able to create an editorial board?
Recruiting a strong initial editorial board for a new journal is not easy. There are several important criteria:
You need editors with strong reputations, to attract attention to the journal and inspire confidence that it will be well run.
You need to assemble a group that is diverse enough to cover the full range of submissions within the journal's area of coverage.
You need editors who have enough time and energy to do a good job. Keep in mind that most of the good candidates are already overcommitted.
You need editors who are committed to the success of the journal and who are eager to inform the community about it and solicit submissions.
Ideally, you have a great idea for a journal that fills a troubling gap in the publishing landscape, and prominent people you mention it to say "What a wonderful idea! How can I help?" If that's the case, then you will still have to make wise choices and put in a lot of hard work, but your chances of success are reasonable. On the other hand, if you have to convince people to join the board, or to restrict your attention to people who are eager to join any editorial board that will take them, then you'll have a much more difficult time.
If you don't yet have enough connections in this field to identify and recruit the right people to join the board, then founding a journal is a bad idea (and it would be wise to wait for a point in your career at which you'll be better positioned for success). I don't mean to be harsh, but your question does not inspire confidence. If you do a poor job of setting up a new journal, it will be a negative for the academic community, and it's not easy to do a good job.
After doing all he initial work about setting up a journal now I want to know how will I be able to create an editorial board?
Maybe I'm reading too much into this sentence, but it comes across as suggesting you view the initial work as the hard part. From my perspective, anything that comes before assembling the editorial board is easy compared with the scholarly and management decisions that will follow. The formalities of setting up a journal are easy (which is why there are so many low-quality journals); the hard part is building a high-quality journal that that achieves all your academic goals and operates stably and successfully for many years to come.