unable to make changes

Hi there,
I have moved my existing website to new domain on same hosting using Duplicator.
i am using theme WP highend on http://www.sefarointernational.com
my questions are:
1) Why i am having difficulties logging in to dashboard, even though password is correct i have to try twice or thrice to get inside. it says password or email incorrect.
2) Whenever i make changes in dashboard like changing Site Title or change some text on my sliders its not saving any changes and showing the old Title and text.
do i have to delete some files to get it done? thanks in advance.