Common record types
A points to an IPv4 server address, CNAME creates an alias, MX routes e-mail, and TXT stores SPF, DKIM, DMARC and verification codes.
Before changing a record, save its old value, TTL and target.
How to reduce risk
Apply changes one at a time and test the result. When moving e-mail, pay special attention to MX and TXT records.
For Hostilla.pl services, support can help verify that records match hosting and e-mail configuration.