Depending on who the person behind the fake profile is targeting, you will likely see friends that are predominantly of the opposite sex of the requester since that is likely who they are targeting when they send out their fake friend requests.
You likely won't see a lot of day-to-day activity on a fake profile because of the effort required to generate 'real' content.
You may see some pictures, perhaps some links, but you probably won't see a lot of location check-ins or status updates.
This information may include your contact information (for spamming), or other personal information that might be useful in setting you up for a phishing attack.
You may also get requests from attackers that post malicious links to malware or phishing sites which may end up in your Facebook newsfeed after you accept their friend request.
If you can't recall ever meeting this person in real life or meeting through any mutual friends, then it is likely a friend request sent to you under false pretenses.