During The Force Awakens, we find out that
Kylo Ren was once Luke's apprentice before going over to the Dark Side.
Until we discover
Rey is also a force user,
are Kylo and Luke thought to be the only remaining Force users in the Galaxy?
There's not yet canon proof, but there's a strong implication in TLJ that "a handful" of the Luke's Academy Jedi trainee students who left with Ben Solo after his tiff with Luke (and were already turning dark before that) became Knights of Ren. As such, there's a high probability they were still alive and thus were "force users left" during TFA timeline.
Additionally, there's also a strong implication that the stable boy at the end of TLJ used the Force to lift the broom, though that lacks definitive canon proof either.
In the film, we don't know of anyone who explicitly acknowledges any remaining Force users aside from Kylo Ren and Rey.
It's kind of implied by Ren that Snoke is a Force user, but even that is not stated 100% clearly, just that he "trained" Ren (and also implied when Snoke tells Ren to bring Rey to him when Ren fails to read her mind for the map).
Supreme Leader. I can get the map from the girl. I just need your guidance.
If what you say about this girl is true, bring her to me
Maz Kanata comes close to outing herself but doesn't quite do it:
The belonging you seek is not behind you. It is ahead.
I am no Jedi, but I know the Force.
We know from narrator - e.g. Visual Dictonary - that Maz Kanata is Force Sensitive. But we don't know that anyone in TGFFA knows of that except for Maz herself; and her words to Rey can easily be interpreted as simply knowing stuff about the Force theoretically, the way Han talks about it.
Nobody knows if Knights of Ren are Force Sensitive as of now. Nobody knows what happened to Inquisitors, or Kanan and Ezra, or any other Jedi that may have survived Order 66.
In the trailer - but the line wasn't used in the film - Luke's voice acknoweldges that Leia has the Force (and obviously, Leia knows she does from the end of Episode VI)
The Force is strong in my family... my sister has it.
Snoke implicitly acknowledges that there are other Force users, because Luke will train more Jedi:
... Leading them to the last Jedi.
If Skywalker returns, the new Jedi will rise.
Seated in shadow, the tall, slender form loomed over the other two men. Other than the face, only long, spindly fingers showed from beneath the dark robe. “The droid will soon be in the hands of the Resistance,” Snoke declaimed, his voice deep, soothing, and very much that of someone in complete control, “giving the enemy the means to locate Skywalker and bring to their cause a most powerful ally. If Skywalker returns, the new Jedi will rise.”
Obviously, from prior canon (Prequels), we can surmise that Force sensitive children keep being born, but that isn't stated as known truth in Episode VII except as implication of the last point.
So there are some known (to us) force users. Leia, Snoke even Maz at least.
In universe it would depend on who you are.
Most of the general public
Would not know if the Jedi really existed. Luke Skywalker is a legend. The force is a little known religion. Kylo Ren seems little known, even if he was he may not be a known force user.
Someone with intimate knowledge of the Resistance and First order
Consider Lor San Tekka for this point of view.
He knows of Luke and Kylo Ren. He is also likely to be able to assume that there are a number other people with force affinity who have been born, since the empires purges, but not trained (or awakened).
He may or may not be aware of Leia and Snoke being force sensitive.
Trained force users
Every other force user seems to be aware of the others we know of. Leia knows Kylo Ren is still alive. Snoke knows Luke is.
It has been shown a number of times that using the force creates a disturbance. Vader and Palpataine could sense Luke once he started using the force. Snoke and Ren can sense Rey.
So they would be very aware of new force users. If there were others who were actively using the force (and not masking it) it would become very obvious.
The fact that Rey's awakening is so clearly and quickly noticed shows that there are unlikely to be many (if any) other active force users in existence.
As Snoke makes clear that Luke is the last Jedi.
I doubt it because
Luke was training a group of Jedi. Ben perverted this and became Master of the Knights of Ren. There is then a shot of Kylo with the other Knights of Ren, they may have light sabres, though whatever they are holding are not ignited. Due to the comments of Snoke about "Even the Master of the Knights of Ren..." when talking about the force implies that the other Knights of Ren to be force users as well