Here's how I modify the Adobe default choices.
Lightroom has "secret sauce" default settings on many parameters. These settings are what the Adobe engineers in charge thought looked good in the 3 minutes(?) they took to evaluate how to handle a given camera's files.
Luckily, the adjustment/elimination of Adobe's choices in these settings is easy.
1. Find a file that looks basically good or very close to good overall.
2. In the Develop module, correct all the Adobe default settings that annoy you. Sharpening, Texture, Contrast, etc. Set them all to zero if that's your preference.
3. At the top of the left-side Presets column, click the + symbol and click the Create Preset choice here. You are given a selector to include or exclude any of 43 settings. Best to exclude Exposure and White Balance at this stage. Also, exclude all of the Transform and Effects settings from the custom User Preset you are in the process of creating.
4. Give this new User Preset a name, and click Create
5. In the Import screen, when getting ready to import new files into Lightroom, in the right-side column, find Apply During Import. Find and select your new User Preset. Now you are applying your own customized settings to the files as they are imported.
6. You can also apply this new User Preset to previously imported files.
Eventually, you may find yourself creating a number of these User Presets for many different looks.