We need to give more context to that word - fear. Its a big stumbling block. I've attached an article addressing it from a Jewish perspective, but it agrees with my understanding of it as a Christian:

https://firmisrael.org/learn/hebrew-meaning-of-yirah-what-connects-fear-and-awe/

the first commandment says to worship no other than the One God... this is because anything else is a symbol or a creation, and by creation i mean for example a person or a society of people

to worship is to fear, because you understand that the object of fear controls your fate

so, what the first commandment is saying is that nothing in this universe is worthy of your fear compared to God, and so it is a command to be fearless towards all else