Both verbs are in the infinitive form. You are right, говорить is imperfective and поговорить is perfective.
The conjugations are as follows:
Past
Imperfective
говорил (masculine singular)
говорила (feminine singular)
говорило (neutral singular)
говорили (plural all genders)
This can roughly be translated as "have been speaking", "were/was speaking", "spoke".
Perfective
поговорил (masculine singular)
погоыорила (feminine singular)
поговорило (neutral singular)
поговорили (plural all genders)
This can roughly be translated as "have spoken", "spoke".
Present
Я говорю
Ты говоришь
Он говорит
Мы говорим
Вы говорите
Они говогят
This can mean "I (you, he, she, it...) speak, am speaking"
The perfective form, since it is perfective, when it is conjugated... it automatically is conceived as future. It has the same endings, as the imperfective version in the present, but it does not convey a present meaning, but a future one.
Future
Я поговорю
Ты поговоришь
Он поговорит
Мы поговорим
Вы поговорите
Они поговогят
This can be translated as "will speak", "will have spoken".
The impefective future is:
Я буду говорить
Ты будешь говорить
Он будет говорить
Мы будем говорить
Вы будете говорить
Они будут говогить
This can be translated as "will speak" or "will be speaking.