Hi DesertS,
Welcome to modular :-)
The best way is, to get an audio interface that has at least (stereo) output. If you like to have input possibilities as well then you need both input & output. A nice example is Intellijel - Audio I/O.
Eurorack signals are (much) higher than line audio signals hence the need of an audio interface module. Some members here save money on such interface and by turning down the gain completely on the external mixer and then slowly pulling it up to see if it goes well.
If you are going to do a lot with DC signals, it's recommended to use an audio interface so you wouldn't have DC signals towards your speakers (since DC would destroy your speakers).
Up to you. Have fun with your modular system and kind regards, Garfield Modular.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads