Because one of my sons is infected by withe COVID-19, all of my family members shouldmust stay at home for a week. Because one of my sons is infected with COVID-19, all of my family members must stay at home for a week.

It isn't wrong to say, but ‘must’ or ‘have to’ sounds more natural👍

Because one of my sons is infected by thehas COVID-19, all of my family members shouldhave to stay at home for a week. Because one of my sons has COVID-19, all of my family members have to stay at home for a week.

Because one of my sons is infected by the COVID-19, all of my family members shouldmy whole family has to stay at home for a week. Because one of my sons is infected by the COVID-19, my whole family has to stay at home for a week.

"all of my family members" is okay, I just feel like "my whole family" is a more natural way to say it. "should" is too lax, it feels like a suggestion.

My wife and I did the remote work, and my first son, who is in an elementary school, studied remotely. My wife and I did remote work, and my first son, who is in an elementary school, studied remotely.

It might sound more natural to say, 'we worked remotely' OR 'worked from home'. You can also say, 'switched to online learning'. We'll usually say 'is doing online learning', 'took online classes', 'took his classes online (from home)'.

My wife and I did the remote workworked from home and my first son, who is in an elementary school, studied remotely. My wife and I worked from home and my first son, who is in an elementary school, studied remotely.

My wife and I did the remote workworked from home, and my first son, who is in an elementary school, studied remotely. My wife and I worked from home, and my first son, who is in an elementary school, studied remotely.

This was the first momenttime that my son has studied remotely at/from home. This was the first time that my son has studied remotely at/from home.

You can also say, 'This is the first time that my son has tried online learning (from home)'.

This was the first momenttime that my son studied remotely (at home). This was the first time that my son studied remotely (at home).

This was the first momenttime that my son studied remotely atfrom home. This was the first time that my son studied remotely from home.

So we weren't familiar with the system, and we faced many issues during classes. So we weren't familiar with the system, and we faced many issues during class.

Fortunately, we finally finished all classes of this week without any big accidentmishaps. Fortunately, we finally finished all classes of this week without any mishaps.

To express this idea, we can say 'without any mishaps' (formal) OR 'without a hitch' (casual)👍

Fortunately, we finally finished all classes of this week without any big accidentproblems/issues. Fortunately, we finally finished all classes this week without any big problems/issues.

Fortunately, we finally finished all classes of this week's lessons without any big accidentissue. Fortunately, we finally finished all of this week's lessons without any big issue.

Tomorrow, we will check again, whetherto see whether we are infected or not. Tomorrow, we will check again, to see whether we are infected or not.

Tomorrow, we will check again, whether my son is infected or not. Tomorrow, we will check again, whether my son is infected or not.

or if you are all ill "whether we are infected or not"

Tomorrow, we will check again, whether infected or nottest for COVID again. Tomorrow, we will test for COVID again.

I hope that no one has a problem on'fails' the test. I hope that no one 'fails' the test.

You can also say: - I hope we 'pass' the test. OR - I hope our test results are negative.

I hope that no one has a problem on the testtests positive. I hope that no one tests positive.

or "I hope no one has the virus

I hope that no one has a problem on the testtests positive. I hope that no one tests positive.