Belanja hari ini

Correct!

Tadi malam, saya membeli pot aroma di toko/toserba.

Anda bisa membeli apapun di toko/toserba di Jepang. 

The right one is "pot aroma" not "aroma pot" :)

Convenience store in Indonesia can be called "Toko serba ada" or we usually called it "Toserba". It's like 笑う sometimes abbreviated into w in Japanese

For example: おはよう笑ーー＞おはようｗ

You can also call convience store "Toko" in Indonesia. "Toko" has the same meaning as 店 in Japanese

Saya memilih bau jeruk manis.

ミカン in Indonesia is called "Jeruk", "Oranye" is a type of color (色）in Indonesia, in Japanese it's called "オレンジ”

シノダさんこれからもがんばってくださいね！

Belanja hari ini.

This is correct, but I suggest you to not include a time specification in the title because it's somehow unnatural. You could use Belanja Harian, or Pengalaman Saat Belanja, for the title. Or other advanced title because your Indonesian skill is already good.

Tadi malam, saya membeli aroma pot di convenience store.

Convenience Store = Toko Serba Ada, or shorten as Toserba. This acronym is widely known in Indonesian.

And unfortunately I can't find a specific name to describe that kind of pot, maybe because it's not popular in Indonesian culture. Similar item to that maybe Tempat Lilin. But for Aroma Pot, If you translated it from English, then it should be Pot Aroma in Indonesian.

Anda bisa membeli apapun di convenience store di Jepang.

Saya memilih bau oranye manis.

Oranye is a color name, for an orange fruit, the right word is Jeruk.