Do i have to learn Pseudocode for IGCSE Computer Science

If you can answer the questions using 'a language of your choice', then it means exactly what it says - you can choose Python if you prefer, or you can choose some kind of psuedocode. Just pick whatever you feel most comfortable with.

Psuedocode isn't a real language - it's just a way of using simplified plain English to describe the flow of an algorithm. A lot of people just invent their own pseudocode, and usually write in a style which resembles whichever real programming language they're most familiar with.

The exam board might have their own style of pseudocode which actually appears in exam questions - so you might be asked to read some pseudocode - for example, a question which asks you to write a trace table, however if you're confident in any real programming language then reading and understanding pseudocode should be easy.