Or the network website that shows the soap opera you like such as CBS.com or ABC.com or NBC.com etc
You can use YouTube but you have to wait for someone to upload the latest episode and sometimes they only show clips.
Go on the website of the station the soap is on and you probably could find the episode you missed.
Also go on the website of the soap itself and you also might find a listing of the episodes by date.
You could also read a recap of the episode on soapoperadigest.com or soapcentral.com
Yes you can download via torrents if you want to do it legally, you can search on youtube or on the websites of the network.
Yes I would suggest You tube.