The present tense in German is mainly used:
• to refer to events that are happening at the present time:
Peter trinkt ein Bier. Peter is drinking beer.
• to describe habitual actions and general statements:
Sonntags treffen wir unsere Freunde. On Sundays, we meet our friends.
Die Erde dreht sich um die Sonne. The earth revolves around the sun.
In addition, the present tense in German often refers to the future when the context makes this clear:
Morgen fährt sie nach München. Tomorrow, she will go to Munich.
There is only one present tense form in German.
Note that German has only one present tense form, which corresponds to all three forms (the simple present, the progressive present and the emphatic present) that exist in English:
Ich arbeite = ‘I work’ (simple present)
‘I am working’ (progressive present)
‘I do work’ (emphatic present)