1. Quest and progress your path at the same time.
WildStar's path system is unique. In order to save yourself time while leveling you should work on both your path and your regular leveling progress at the same time. As you quest through an area, make note of where your path objectives are and do those at the same time. This will help you progress both your path level and your normal level. It will also let you gain the most experience for your time.
2. Stay on your toes.
WildStar can be a challenging game. There's a lot to worry about even while leveling. You'll need to be on your toes and watch out for ground effects, environmental effects and enemy attacks to avoid, dodge and interrupt/stun. Some abilities also take a bit of practice for learn. Skill shots, for example, on most caster classes may take some practice especially if you're a healer. Level with survivability in mind and learn how to avoid any type of damage you can while gaining familiarity with the combat system.
3. Choose a spec and playstyle that suits you.
Since combat can be a little challenging especially if you are new to MMORPGs, you should make sure to pick a class and spec that suits you well. Don't choose a role you are unfamiliar with until you learn the basics of the game. Remember that each class can perform two out of three of the trinity roles. If you need to switch to a DPS role in order to quest easier, do so. Similarly, if you plan on learning how to tank and/or heal and feel you need practice, there's nothing wrong in leveling as that spec and doing dungeon runs to prepare yourself for the road ahead.
4. Complete each area before moving on.
WildStar has many intricacies hidden within each zone. There's a lot to explore, so take your time while leveling and see everything there is to see before moving on. In every zone there is reputation to gain, unique rewards to earn, cool storylines to take part in and path progression to explore. Explore each quest hub thoroughly before moving on and keep on the lookout for quests in remote areas.