(a) Any person of the age of 18 years or older who is not otherwise incompetent may bring, file, prosecute, defend, litigate, settle, dismiss or otherwise compromise any action in law or in equity in any court without the interference or appointment of a guardian, guardian ad litem, next friend or other legal representative.
(b) Any person of the age of 18 years or older who is not otherwise incompetent may be appointed by any court as guardian ad litem, next friend or other legal representative of a person who has not reached the age of 18 years.