I use mine mostly for travel since it is cross-body and goes flat in my suitcase. I have the PM and it doesn't hold a lot. I tried the GM and it got too heavy for me.
I think it's a great first LV bag and it won't be your last! You should definitely pick something you will use more, rather than a dressy bag if you mainly go casual.
I think it's a GREAT choice!! I have the GM and LOVE it, it can be dressy or casual, depending on what you are wearing...the GM fits a tons and never gets heavy...good luck deciding!
I got the pm as my first Lv...I'm loving it, use it most days, great for travel with hands free to hold my kids. Since then I have bought the new Rivington Gm and damier zippy wallet. Go for it... it will be a start of your lv addiction