Since I grew up in a mostly Slavic Catholic neighborhood, on Good Friday almost everything shut down between noon and 3 pm but the churches were open to come in to as priests were doing the Stations of the Cross. It was also a day of fasting (one meal or a couple small meals) and no meat.
On Saturday you could go to church or the church hall and bring a basket with some of your Easter dinner items and a priest would bless it.
On Easter Sunday the Catholic churches would be pretty packed as all good Catholics were expected to do their Easter Duty and attend Mass. Many who did not come regularly usually made it to the Easter Sunday services.
Kids would get their Easter baskets filled with goodies in the morning and then families would get all dressed up to attend the Easter Service. Afterwards there would be large family gatherings for a huge feast that usually included all the eggs the kids colored and at least one butter lamb.
Butter lamb - Wikipedia