Hallo Big Sam!
The postcard is (mostly) written in the so called Kurrentschrift. This was the common style of handwriting in the 19th and early 20th century in Germany. The writing of the postcard is actually not that difficult to read for someone who is used to that kind of scripture, like my grandmother was or a former student of mine, who used to write every classwork that way, which made correcting his work for me not an easy task, because I’m not that used to it. Nevertheless, I like to decipher old letters or postcards. So I tried my very best to read and translate it. Here is the result:

[Right part of the postcard:]
(To) Mr
Paul Karte
Burgstädt (in Saxony)
Kolonialwaren

[Left part:]
(From the) Landsturmmann
Gusl. (Gustel = Gustav?) Dietze, Ol (?) K. XII
13 K[???]alschaft
Lindenhof Zittau [Sachsen?]

[Under the line:]
Lieber Paul (und) Frau Karte
Ich bin nun schon über 4 Wochen bei Soldatens u[nd]
(es) geht mir soweit ganz gut
Hoffe dasselbe auch bei Euch.
Wenn Du alte abgelagerte(?)
Cigarren übrig hast (,) die finden hier gute Verwendung
Seid herzl(ich) gegrüßt [???] von
Eurem Gustel (?) Dietze

Translation:

Dear Paul (and) Mrs Karte
I am now for more than 4 weeks at the soldiers and
doing quite fine so far.
Hope the same for You.
If You have old matured cigars left, they find good use here.
You are warmly greeted from
Yours Gustel Dietze

The sender obviously was a recrute of a reserve-unit of the Landsturm (2.Landsturm-Infanterie-Ersatz-Bataillon/XII.Armee-Korps); it was stationed in Zittau in Saxony. The soldiers of the Landsturm were the reservist of the imperial army. The addressee himself ran a Kolonialwarenladen, i.e. a grocery shop.
Mr Dietze wrote to him in a rather matey and colloquial manner.