♥︎ The petticoat
Everyone knows that a petticoat is needed to make your skirt look nice, so that's your first item on your list if you want to start out with lolita.
No petticoat? No lolita, even when you are a casual lolita you still need a small petticoat to achieve the bell shaped look that is specific for lolita. Some skirts and dresses have a build in petticoat so there is no specific need to add another petticoat in the first place, but I would highly recommend it you add an other one to make you outfit perfect!
♥︎ A blouse
An other item on your list is a white or black blouse you can choose for the detachable sleeves. Or just choose between short or long sleeves. For a first blouse I would suggest a blouse with detachable sleeves, it gives you basically two blouses in one. Short sleeves for those warm days and long sleeves for the others. White and black are two basic colors that can be used in every style. If you choose a coloured blouse your options are limited for combining all the items in your closet.
♥︎ A skirt or a dress
Both items are great starters, but some people are more skirt types than others. If I take a look at my own closet I immediately can tel you that I'm a dress person. If you go for a skirt there are two options, first one is to choose between a non print skirt or a printed one. Non print skirts are much easier to combine in other styles if you are still searching for your own style, a printed skirt are a bit more style specific though there are some prints that can be used in different styles if you choose the right color way. Even with a black floral skirt you can make it work for a sweet lolita outfit or a classic one. It's just a matter of practice and combining the right items together. When you go for a dress the options are the same as a skirt, go for a printed one that is easy to combine in different styles or a solid color one. When it comes to dresses you can choose between a JSK (Jumper Skirt) or an OP (one piece). The difference between the two are the sleeves, JSK dresses got no sleeves and the OP dresses got sleeves, sometimes short ones or long ones depending the design of the dress. You need to be aware that you need to wear blouse under need a JSK or wear a vest to cover up your shoulders.
♥︎ A nice jewelry set
Jewelry makes every outfit complete, it can be a nice vintage necklace from your mom or just a bracelet that you find in a mainstream store. In my eyes pearls are the best for every style, it's something timeless but still very easy to combine. You don't need to spend hundreds of dollars for a jewelry set, if you shop in your local accessory store there are many items that can work with lolita.
This is also an important item in your wardrobe, you can choose for knee socks, over knee socks or tights. It's also possible to choose ankle socks with lace on top although I wouldn't recommend these as a basic item. You can pick every color you want but if you are not sure about your stile I would choose a white pair or a black pair, they doesn't have to be solid in color is you find nice ones with a print on it that is easy to combine with many other items you can always choose those.
You can always expand your wardrobe with extra's like head bows, flowers, cute shoes, vests and other items that work with lolita. But the guide I've posted today gives you a good start for the first items of your wardrobe. Things like shoes are also important but if you look into your closet you probably have already a pair that works with lolita just like headwear, if you style your hair and add a cute hairpin it's already a good start. You don't need 20 bows to make your hairstyle lolita, it's all in the little details.
I've made some coords with the items above, so you can see how easy they can be combined to find a perfect outfit for you.
First up are the classic/sweet outfits, it's a bit harder to make an all sweet outfit when you only have white or black basics, but if you change your hairstyle to a more sweeter style it works as well.
This skirt can also be paired with pink tones to make it more of a sweet style.
Add some bows in your hair and tea party shoes for that extra sweet touch
On to the more gothic style coords of these items, you basically get rid of the white blouse and socks. And replace them with a black version. These are not your typical gothic lolita outfits but they work great in defining your style. To add the extra touch of black use dark hair accessories and shoes.