There is not any option provided by sololearn to compare two persons but still you can compare manually on the basis of likes ,skills,followers,challange graph and badges.it will not be absolute but will produce a rough sketch of comparison
you can manually compare activity on sololearn with other users. again, activity. as they can have cool personal projects that they don't post here, or learn concepts and they don't keep the associated codes here.
All the levels and badges do not reflect the real situation from time to time. Also if I am asked I will try to have fun while learning something new and be unique and not compare too much with the other users.