After entry: residence permit and registration
Getting the X1 visa and entering is only step one. By law you must apply for a student residence permit with local immigration within 30 days of entry — the deadline comes from the Exit and Entry Administration Law and has no grace period. Overstaying is illegal residence and harms future China applications.
After you submit, immigration usually keeps your passport for about a week. You cannot leave China during that window, so do not book cross-border travel beforehand. Many Thai students submit just before a holiday and end up stuck in the country.
Accommodation registration is separate. On-campus housing is registered by the university; if you rent privately you must register with the local police station within 24 hours of moving in. Skipping it is an administrative irregularity even with a valid residence permit, and can bring a warning or penalty.