Foundation rows are great for adding extra stretch if you don’t want a ribbed edge but also great for long chains by doing the chain and first row at same time. They are also great if you tend to twist your chain when joining in round.
To do a SC Foundation chain 2, DC foundation row chain 3 to start.
YO pull through one loop. (shown below) This is your chain created.
YO pull through 2. You have now made your first SC and chain.
This is a row of foundation sc’s
For DC row you start with chain 3. YO insert into 3rd chain from hook (first chain you made) and pull a loop through. Like before you YO pull through one to create a chain then complete like a normal DC- YO, pull through 2, YO pull through 2.
If you’re still struggling there’s lots of videos online that may help you more.