In the United States:
We fast on Ash Wednesday and Good Friday.
We abstain from meat on all the Fridays of Lent.
More information is available here: usccb.org/prayer-and-worship/liturgical-resources/lent/catholic-information-on-lenten-fast-and-abstinence.cfm
More explanation from the bishops’ web site:
**Q. I understand that all the Fridays of Lent are days of abstinence from meat, but I’m not sure what is classified as meat. Does meat include chicken and dairy products?
A. Abstinence laws consider that meat comes only from animals such as chickens, cows, sheep or pigs — all of which live on land. Birds are also considered meat. Abstinence does not include meat juices and liquid foods made from meat. Thus, such foods as chicken broth, consomme, soups cooked or flavored with meat, meat gravies or sauces, as well as seasonings or condiments made from animal fat are technically not forbidden. However, moral theologians have traditionally taught that we should abstain from all animal-derived products (except foods such as gelatin, butter, cheese and eggs, which do not have any meat taste). Fish are a different category of animal. Salt and freshwater species of fish, amphibians, reptiles, (cold-blooded animals) and shellfish are permitted.
**Q. I understand that Catholics ages 18 to 59 should fast on Ash Wednesday and on Good Friday, but what exactly are the rules for these fasts?
A. Fasting on these days means we can have only one full, meatless meal. Some food can be taken at the other regular meal times if necessary, but combined they should be less than a full meal. Liquids are allowed at any time, but no solid food should be consumed between meals.