If you give your Data Discs to the Research Center, you will get new Blueprints that allow you to create things. These Blueprints will not be obtainable in any other way, so a lot of players prefer to get these Blueprints early on in the game. Some of the things you can make from these unique blueprints are Cooking Set, Fish Tank, Blender, Printing Press, Water Well, or the Industrial Cutter. So there are a lot of great things from these Blueprints!
If you chose to use the Data Discs at the Church Store, you get to buy unique seeds and items such as the Large Planter Box, unique Tree Seeds, or the Irrigation Flooring. The stock resets daily, do you can buy multiple of each thing by returning at a later time.
Many of the Data Disc items from the Church Store are actually very good, so you might want to get a few of those as well. Some players prefer to get all the Blueprints they want first, while others want to focus on making a good farm first. It's up to you!
How to get Data Discs in My Time At PortiaAll Data Discs are obtain by mining in the Abandoned Ruins. The drop randomly in the entire mine, but seem to have a higher drop chance at relics and other special blocks. They can not be tracked with the Relic Scanner, but it's nice to use anyway, since they often drop alongside other Relics.
Anyway, the best way to farm them is just to spend a lot of time mining, and there is really no direct method of farming these by themselves.