Flair Signature Espresso brewing questions

So I have a kettle that only does boiling (no temperature control), how long should I have to wait until I can pour post-boiled water into the portafilter chamber?

I have two portafilters in the Signature bundle (standard portafilter and the bottomless one). However the post-brewing cleaning seems to be arduous with the standard portafilter since you can’t remove the cap on the bottom whereas the bottomless portafiltercan. How do you actually clean the standard portafilter and fully rinse off the residual espresso between the shower screen and the black plastic piece shaped like a sippy cup?