Three things I wish I was told when I was a new Lolita
"Offbrand" Lolita doesn't work really well..
My first outfits consisted of dresses from h&m or New Yorker. I think I looked cute for what it was but it's not sooo Lolita. You can make mistakes when you are new (when if not then?) but I would recommend to invest in a real Lolita piece. It doesn't have to be a brandnew Angelic Pretty/ Baby/ Moitie/ whatever item but something second hand or Taobao is also okay for girls with a low budget. When you have a better feeling for what looks good and what not, it's totally cool to mix with offbrand items but it's harder for beginners to make a proper Lolita outfit out of non-Lolita items. After my first outfits, I bought dresses from Taobao which improved my style immensly.
Lolita is a hobby (for most of us) and a hobby costs money. Lots of it, if you want to do it properly. If you like pimping your car, you have to invest in new pieces, if you like taking photographs, you need a good camera with different lenses. It all costs money. It doesn't have to be the most expensive but a hobby costs money. I was very sting with buying Lolita stuff at first. A dress for more than 150€? No way I would ever pay this! (Now I have dresses that cost double of it x_x) So I tried to make the best out of my wardrobe and failed completely. When I bought a good petticoat and paid (if I remember correctly) 80€ for my first real Lolita dress set (by Lolita Princess from Taobao) my style improved. Same goes for shoes. I repeat but I DON'T mean that everything has to be brand - by far not! But to have a good basic equipment, you have to invest money and don't try to be toooo avaricious. Because then you may have to buy twice.
Don't get too colorful
There are so many pretty pieces in all the pretty colors. If you are a beginner, your mind screams "BUY AAAAALL THE STUFF!" but if you haven't put up a wardrobe of basics (white blouse etc) yet, don't try to buy too many different colors and styles. It's easier to mix and match if you have a kind of "color code". Try to buy one outfit you like and not many different pieces that don't match. Hope it gets clear what I mean. Having gothic dresses and sweet blouses doesn't make any sense, you should buy matching items.
Maybe this doesn't help every Lolita newbie but it would have helped me ^^" I learned a lot over the years and I'm still learning. It never ends ^_^