Dificulty making a field required and disable and required

hi i have trouble in 2 things.
1st when i run a task i see 3 options when i select option 1 it will display field 1 and if 2 it will display field 2 and if 3 it will dispaly field 3. i want the displaying field to be required in order to submit. so if i select option 1 i want field 1 to be required and field 2 and 3 not required. i cannot get that no matter what i try

2nd when i submit the form i want only to see the fields with value in it i dont want to see field 2 and field 3

if any on can help i have been trying to get this done for 3 days now

can anyone look into this??