The reason for this is that Covid-19 hit very hardreally hit the old people here, and I was afraid of infecting her.

The other author's correction more directly corresponds to what you are saying, but thought I would offer this correction as an alternative as well. Also, "Really" could also be replaced by "strongly" here, but not "very"

It isn't common that neighbors allow people who don't live in the urbanizationneighborhood to get into the swimming pool, even less now with COVID-19.

I find your use of "isin't common" and "even less now" to be fine.

The reason for this is that CovidOVID-19 hit very hard the old people very hard here, and I was afraid of infecting her.

In the afternoon, I went to a friend's swimming pool in her urbanizationneighborhood.

"urbanization" means "the process of making an area more urban", so that's not what you meant. I'm assuming you meant neighborhood?

It isn't 's uncommon that neighbors allow people who don't live in the urbanizationneighborhood to geto into the swimming pool, even less now withspecially now due to COVID-19.

I cleaned the sentence up a bit - "isn't common" can be changed to "uncommon" and it sounds much smoother that way

These have beenWe've had some very hot days recently, so I enjoyed it a lot.

Later, we went over to her house, and now I'm currently drinking a coold beer while I am writing this :)

We are playing Risk most likely this likely going to play Risk tonight, after dinner.

I drinktoast to your health!

I hear "I toast to" way more often than "I drink to", but I would change this sentence to:
I wish you good health!