Hey there. It's pretty normal to not remember your dreams if you are just starting out.

Something you can do is tell yourself every night before you go to sleep:
"Every time I wake up I will remember my dreams."

It might not sound like much, but just keep thinking about dreaming and you will start to remember your dreams!

Also, have you tried waking up in the middle of the night and remembering the last thing you were dreaming about? I did this a couple of times when I was first starting out with my dream journal and it really helped. Just remember to think about your dreams every time you wake up, because I find that if I forget to do that, then my dreams are lost to me.

Hope that helps!