how to apply salesforce user specific permissions?

Question

i have a system on salesforce that i should create a USER X have the permission

1- see the assigned data only

2- View accounts and contacts data only

3- Edit and create oppo.

4- make some fields read only

5- only see the current application

can anyone help me for this as am new on sales force

Answer 1

I went to setup -> Administrator -> Security Control -> Field Accessibility And from there ,, you should find all the fields and the objects to modify the setting for a specific user