2 or 3 A Level subjects?

I want to take 2 subjects as I am poor at maths. I want to take Business studies and Accounting Am I going in the right way?

Universities usually require 3

What would you do instead of a 3rd Alevel?

Nothing, just wanna do these two subs for AS and A2

Really depends on what you want to do. Univeristies do mostly ask for 3, and all top unis do. WHy not take a facilitating subjects? Some unis look down on lack of facilitating subjects (like Maths, English, Sciences, Geography etc.). Also if you are bad at maths, you may find Accounting and Business pretty tough anyway. Really would recommend taking 3 A levels if you can and depending on what you want to do in the future.

Ik it's weird but I am really good at Accounting and Business Studies. Should I take Law as my third subject?

Take a third. If you hate it / do bad then drop it.

Doing bad won't affect?

If you want to go to university, then probably not, sorry. Most universities need 3 A levels to make an offer, but there might be some that don't, look into it.

But if you are doing bad it won't look good on Uni applications.

Then should I take Economics or Law? I am bad at maths that's why I don't wanna take it

That's the reason I am afraid of, I got 'D' in IGCSE and I am repeating it.

I very strongly advise against it. Accounting and Business are pretty much useless without Maths to accompany them.
Maths is the most important A-level

May be A-Levels are not for you.

Why not do A Level 3 BTEC Extended Diploma in 1 thing you enjoy, available at many colleges?

It can still get you to Uni.