Sure, I can show an example that you can then adapt for your app.
Patch(
collection_Name_from_ITEMS_gallery,
Defaults( collection_Name_from_ITEMS_gallery),
{ SkillName: txt_Skill.Text,
ExperienceLevel: dronDownExperience.Selected.Text,
ProficiencyLevel: dropDownProficiency.Selected.Text } )
collection_Name_from_ITEMS_gallery - replace this with the datasource you have at Items property of your gallery
SkillName, ExperienceLevel, ProficiencyLevel - replace with columns name from your datasource
txt_Skill.Text - replace this with the name of the text input for Skills
dropDown - these are you dropdowns with Experience and Proficiency, replace with the names they have
dorpDown.Selected.Text - text here needs to be replaced with the proper column name from the dropdown datasource.