I'm currently thinking on a 6300 IP Champion. Here is the thing, I don't have a support yet and that is why i"m thinking about Braum. I am thinking about Jinx because i am a great adc, but the thing with her is I don't know if im That good with her. So, who should i get first? Other less wanted optional are Lucian and Nami.
the better question is what do you like to play better?
i like both jix and lucian but i think jix having that global ult is better jusy my opinion
both nami and braum have good cc but one is a tank one is not
so it all comes down to what style of playing you like best, not everyone likes the same champs. best if you try them when they come on the free rotation and decide for yourself
It all depends on your playstyle, as Dodzh said. You also don't have to buy a 6300 IP champ, as there are some other ones that are really good but aren't as expensive so you can buy other stuff after buying them (e.x. runes).
Anyways, I would like to recommend getting a support as having knowledge in a diversity of roles is always a good thing. There are also other choices for supports including but not limited to 
, 
, 
, 
and 
. Which one you may want to choose depends on your playstyle. Do you want to be a tank like ? Do you want to have a decent amount of CC like or ? Do you want to heal your allies like , or ? If you decide on what kind of role you would like to play you can come back and tell us so we can help you more.
I've been playing a lot more ADC lately, and I value Lucian over Jinx. They're both very strong, and I would go with whichever your personal preference is; but Lucian's mobility in a fight seems better to me.
In order I would advise: Lucian, Jinx, Nami, Braum.
I think Braum is a fairly difficult champion to play well especially in soloQ. Although Nami is squishier, she's one of the strongest supports IMO. You say you don't have any supports, but most midlane mages can work as a support if you play them right (like Annie - 450IP). Just make sure you ward for your ADC and do your best to enable them to farm. If you're already a great ADC then you probably have a good idea of what a great support does and can try to mimic that.
since you dont have a support yet get nami because she is a save ranged healer-type support who is easier than most supports
