Learn Hardcore German: Wir machen morgen einen Termin aus, um alles zu klären. - We will arrange an appointment tomorrow in order to clarify everything.

klären: clarify, clear up ambiguities, settle questions
besprechen: discuss (talk through, not necessarily reach a conclusion)
lösen: solve (find a solution to a problem) In your sentence, klären suggests the aim is to resolve or make things clear.

German ausmachen is a separable verb with several meanings. In the collocation einen Termin ausmachen, it means “to arrange/set up an appointment.” Other common meanings are:

das Licht ausmachen = turn off the light
Es macht mir nichts aus. = I don’t mind / It doesn’t bother me. Context tells you which meaning is intended.

Why is the verb split as machen … aus?

Because ausmachen is a separable-prefix verb. In a main clause with simple tenses, the prefix (aus) goes to the end of the clause, while the finite verb (machen) stays in position 2:

Wir machen … aus.

Where does the prefix go in other tenses and clause types?

Perfect: the prefix reattaches to form the past participle at the end: Wir haben einen Termin ausgemacht.
Subordinate clause: the verb is at the end and the prefix stays attached: …, dass wir einen Termin ausmachen.
With a modal: the infinitive goes to the end, attached: Wir wollen einen Termin ausmachen.
Future with werden: same as modal: Wir werden einen Termin ausmachen.

Why is it einen Termin and not ?