Yes they did in secret rooms in their house
Emporer Constantine
In private homes or isolated places.
The early Christians had to hold secret meetings in Rome because being Christian was against the law. The only religion allowed in Rome was the polytheistic worship of the Roman gods, like Mars, Jupiter, Juno, and Venus. Because the Christians believed in the one God and believed in Jesus Christ, their religion was illegal, and they had to meet in secret to avoid being punished for breaking the laws.
The early Christians refused to worship the official gods of Rome.
Because the Christians would not partake of Emperor worship and because they were somewhat secretive in their worship, believers received the wrathful displeasure of some of the Roman Emperors.
Primarily, Christians worship in churches on Sundays.
A martyr is someone who suffers or dies because of their beliefs. The Christians in Rome were persecuted/killed because they would not worship Roman gods or take part in sacrifices.
Christians do not worship using a mat.
Christians worship God. We often worship with our hands up in the air in worship towards God.
Christians worship everywhere. "other" Christians worship in Isreal, or Nazareth, or Bethlehem.... but Christians still worship everywhere
Emperor Nero of the Julian-Claudian Reign started a fire in Rome and blamed it on the Christians. He used them as scapegoats in order to persecute them because The Patricians, or wealthy class, were atracted to Christianity and if they became Christian they would not "worship" or respect the Emperor because Christians only worship the one true God, and Patricians were the Emperor's power source.