Can anyone help me with my 750pt list? I’m new!

Note: I also have a big Mek, and one of the boys unit is actually a kommandos that im running as boyz. So that could also be changed. I’m playing against necrons and chaos demons. Any tips on how to play would also be very appreciated.

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• FACTION KEYWORD: Xenos - Orks
• DETACHMENT: War Horde
• TOTAL ARMY POINTS: 740pts
• ENHANCEMENT: Follow Me Ladz (on Char1: Warboss) & Kunnin’ But Brutal (on Char2: Warboss)
• NUMBER OF UNITS: 8
• SECONDARY: - Bring It Down: (1x2) + (1x4) - Assassination: 2 Characters +++++++++++++++++++++++++++++++++++++++++++++++

Char1: 1x Warboss (100 pts): Kombi-weapon, Twin slugga, Attack squig, Big choppa Enhancement: Follow Me Ladz (+25 pts)

Char2: 1x Warboss (90 pts): Kombi-weapon, Twin slugga, Big choppa Enhancement: Kunnin’ But Brutal (+15 pts)

10x Boyz (80 pts) • 9x Boy 8 with Boy, Choppa, Slugga 1 with Boy, Close combat weapon, Rokkit launcha • 1x Boss Nob: Big choppa, Slugga

10x Boyz (80 pts) • 9x Boy 8 with Boy, Choppa, Slugga 1 with Boy, Close combat weapon, Rokkit launcha • 1x Boss Nob: Big choppa, Slugga

5x Flash Gitz (80 pts): Ammo Runt • 1x Kaptin: Choppa, Snazzgun • 4x Flash Gitz: 4 with Choppa, Snazzgun

5x Nobz (105 pts) • 1x Boss Nob: Big choppa, Slugga • 4x Nob: 4 with Big choppa, Slugga

3x Deffkoptas (80 pts): 3 with Kopta rokkits, Slugga, Spinnin’ blades

3x Killa Kans (125 pts): 3 with Kan klaw, Rokkit launcha