It says permission denied on that TMP file
Check ownership of this file
ls -lrt /tmp/mongodb-27017.sock
Check if you have any mongod running
ps -ef|grep mongod or try mongo/mongosh depending on your shell
If you can connect means mongod is up
Looks like you brought up mongod as root
If TMP file is owned by root shutdown all mongods and remove that TMP.sock file and start your service again