How to set x1 and x2 from the dataset in pca?

Hello... I have a dataset that i attached... I know all the code but there is a small problem which is x1 and x2... Im doing pca dimensionality reduction which i don't know about the x1(:,?) and x2(:,?) the loading dataset can anybody help please... Thnx in advance The code like this:

numdata=240; %rows Datasetname='df2.csv' ; Dataset=csvread(Datasetname); X1=Dataset(:,?) ; %this is i don't know X2=Dataset(:,?) ; also this...

Aftr this x1 and x2 mean etc