did he participate in any invasions?
Yes, the invasion of Poland.
Helmut Lent
The German plans for the invasion of Poland were conceived under the codename "Fall Weiss" (Case White). This operation called for simultaneous attacks on Poland from three directions, the north, the west and the south, beginning at 04:45 on the early morning of 1 September 1939. On this morning Helmut Lent, with Kubisch as his wireless operator and rear gunner, escorted a formation of Heinkel 111 bombers of I. and III./"Kampfgeschwader" 4 (KG 4) attacking the airfields at Krakow in support of the southern prong of the German attack. 
who was helmut lent? A German night-fighter where was he born? Pyrehne, district of Landsberg an der Warthe, Province of Brandenburg, Germany name an educational institution that he attended. 2nd Air Warfare School
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Helmut Lent [SEP] Invasion of Poland
At this point of the campaign the Bf 110s switched from bomber escort to ground-attack since the Polish Air Force was all but defeated. In this capacity Lent and Kubisch destroyed a twin-engined monoplane on the ground on 5 September and another aircraft, a PZL P.24, on 9 September. On 12 September 1939 he was attacked by a Polish aircraft which shot out his starboard engine. Lent made a forced landing behind German lines. He flew five more missions during the Polish campaign, destroying one anti-aircraft battery. For his actions in the Polish campaign Lent was awarded one of the first Iron Cross 2nd Class () of World War II on 21 September 1939.