You are actually asking two questions:
- in the title – how to pull without merge (I came here for this question, originally;)
- in the description – how to check out a branch without merging in to master
Pull remote branch without merge
# Assuming you are on wanted branch (b1) already
git pull --rebase
No merge, just rebase.
Check out remote branch (from origin)
git fetch
git checkout b1
No merge to master, new branch b1 is created.