Moved from Canada to Texas - Changing Coolants and Engine oils

Hello Experts,

I have a Tucson 2021 2.4L that I bought in Canada. Just hit 100k kms.

1. We moved to Texas last year and have done couple of oil changes with local stores. They always used Full Synthetic but not sure if they used 5W-20 or 5W-30 in it but the cap says 5w-20. However, I have been going through some reditt posts and Quora posts. They said for hotter temperatures 5w-30 should work perfectly unless its very cold in places where you live in to use a 5W-20. Please suggest.

2. About the coolant, as we were in Canada I see there is a pink coolant that have been used previously probably a 50-50 mix. But now, as Im in Texas, I saw in few posts saying that you can just top it off with distilled water if you are not living in too cold climate. Is this ok or should I still use a 50-50mix?

Thanks