fault codes

hi guyes
i recently bought a toyota corolla xse 2018
with 9,000km on it
after just 2 days check engine light came on
with p0420 code no matter how many times i
clear the code it will pop right back
then today while i was driving tpms light
started flashing and i chechked tire pressures
it was all 32psi i tried 33 and 34,35,36,38 it
wont turn off no matter what i do
what the hell is happining?!