Git Error: trailing whitespace, indent SP followed by a TAB, unresolved merge conflict

I have been using Git from last few days, and faced following errors while committing:
1) Trailing whitespace
2) Indent SP followed by a TAB
3) Unresolved merge conflict
The first error “Trailing whitespace” is because of carriage-return/line-feed(windows style line feed/end). To resolve this problem comment following lines(58-60) in .git/hooks/pre-commit file:

if (/\s$/) {
bad_line(“trailing […] Continue reading