It helped me a lot when a friend told me that i do not have to stick to the first name i choose and that it's ok to try things out. I also see in my friend group that a lot of people have several names and use one mostly around their family and for other "public" stuff and then have a "friend name" that we use amongst each other, and usually both of these are official names that are on our legal documents and all.
It's not only ok to experiment, it's a necessary part of transitioning.