Because I have been very busy these, there was a little, I didn't have much of a chance to see my kids this week.

Today, I was also late to cgot home homlate.

or "Today, I was also late to get home" or "Today, I was also late coming home" there are many ways to phrase it.

ForSo I could playing with them this weekend, I bought the toysome Legos.

Two of my kids have never assembled Legos from partsbefore.

Because I have been very busy these, there was a little chance to see my kids this week.

Today, I was also late to cocame home late.

For playing with them this weekend, I bought the toys.

I bought the toys to play with my kids ths weekend. I bought the toys for my kids to play with this weekend.
(Depends on whether you want to stress that the kids are playing with the toys, are that you are playing with them.

These two kids have never assembled Legos from parts.

Because I have been very busy these, there was a little chance to see my kids this week.

Alternatives:
Because I have been very busy, there was not much chance to see my kids this week.
Because I have been very busy, I wasn't able to see my kids much this week.

Today, I was also late to come homecame home late again.

FI bought the toys for playing with them this weekend, I bought the toys.

Your sentence is not incorrect, but this sounds more natural.

Two of kids have never assembled Legos from parts.

Because I have been very busy these last few days, there whas a little chancn't been much time to see my kids this week.

For playing with them this weekend, I bought the toys.

To play with them this weekend, I bought the toys.

TMy two kids have never assembled Legos from parts.

Because I have been very busy theseis week, there was a little chance to see my kids this week.

Because I have been very busy these, tThere was a little chance to see my kids this week. as I have been very busy these days,

Today, I was also late to ccame home homlate.

For I bought some toys for them to playing with them this weekend, I bought the toys.

Two of the kids have never assembled Legostructures/buildings from Lego parts.