You'll be fine. It takes time to understand the combat and mechanics, but once you'll get the hang of it it's a very fun experience. The village quests handed out by Hinoa are like a tutorial, solo-only quests with smaller health pools etc. It's best to try out the weapons there to see what you like the most, and after that you're good to go to tackle the hub quests from Minoto. These are seperated in Low & High Rank and can be played with other people online. If you have trouble at any poimt of time, remember that you can customize your buddies! Palamutes are more damage oriented, while Palicos are supporters with a wide range of skills. There's also the Defender Armor and Weapons which can help you clearing the early game, but since it's made for people who just want to get to the expansion ASAP, it's not adviced for newcomers.

And yes, there are still enough people that play the base game :)