A mercenary is a professional combatant. They travel from location to location acting as a soldier or a bodyguard, or whatever their client needs. While their form of protection varies, they are all well versed in traveling long distances. You don't ask questions, money talks after all.
A mercenary, you deal with the more mundane aspects of adventuring. You are effective at getting from place to place and dealing with the rigors of the road. Because you are a hand for hire, you know how to deal with people, specifically people that need to be found...for what ever reason.
Mercenaries are generally good at physical skills, that is the nature of the job. Generally mercenaries have high Strength and Endurance to reflect someone that has grown accustomed to harsh conditions. Some mercenaries have high Dexterity or Agility in addition to Body skills to round of their general physicality. Mercenaries often have good Acuity for finding their bounties or good Cunning to get what they want without having to resort to violence. Most mercenaries started as a Militia member, or even a Soldier, though it's just as likely to have started as a Criminal or a Bounty Hunter.
Starting skills: Physicality, Movement, and choose one from Speechcraft, Awareness, Survival, or Medicine
General skills: 2 skill rank per level
Skill boosts: 1 skill boost per level
Physical skills: 2 skill rank per level
Equipment
You start with the following equipment, in addition to any other starting equipment:
(a) an explorer’s pack or (b) a dungeoneer’s pack
a pouch containing 10 gp
Marching On
Your years traveling have given you insight on how best to continue marching on. You have advantage on rolls to resist the effects of a forced march, and your overland travel distance in doubled.
Bounty
As an Apprentice, you learn to mark a person as your bounty. This can be within 120 feet visual range, a wanted poster, or a detailed description given to you. You have advantage on Intelligence and Cunning roll made to learn about or find this person.
Interrogation
When you become a Journeyman, against your marked Bounty, you have advantage on Speechcraft (Strength) – Intimidation and Speechcraft (Will) – Coercion rolls against that target.
Fast Camp
At 10th level, you have learned how to setup camp more efficiently. The time to setup camp is halved for you and your party, and as long as you have materials to make some sort of meal, your parties short rest time is halved.
Walk it Off
At 13th level, you can ignore the effects of exhaustion for non-combat rolls for an hour. You must finish a long rest before you can use this feature again.