500pts Blood Angels vs Necrons

I am a very novice gamer and only have 1000pts and my brother only has 600. But we had a game anyway and I did learn some things.

Army lists :

Blood Angels -
Lemartes
3 death company
5 assault marines with power fist
5 tactical marines with plasma gun and power fist

Necrons -
Lord with orb
2x 10 warriors
Wraith

I was severly outnumbered and i think he had 50 points extra but hey


Board was just a little section of my bedroom floor.
We had this theme.
I put down my battle for macragge terrain on my deployment zone and my brothers city ruins on his half.
And on the first game turn all my units counted as they had gone to ground last turn inside the crashed plane (as if the plane had just crashed and they were getting raided by necrons)

Well anyway I didn't get shot at first turn because the necrons moved and weren't in range.
Second turn i advanced Hehe lol
My assault marines moved over the terrain and landed near 1 squad of necrons
My death company went towards the other squad with the tacticals.
Death company and assault squad shot with pistols killing a couple of warriors but the tacticals were out of range.
Nothing was in charge range! just missing by a few cm's!!!

Anyway his turn and he shot at me killing 2 death company!!!
His wraith assaulted my assault marines and he killed one and then i smashed it with my power fist
And his necrons assault my death company (btw the chaplain is in this squad if you haven't realised yet) and no one loses a wound.

My turn and my tacticals lumber forward but nothing that isn't in combat is in range I realise I should have ran but I forgot.
Assault phase I charged his last necron squad with my assault marines. All through the game so far the necron lord is behind a building handing out his res. orb powers. I drop about 4 but only 1 dies next turn because of WBB rolls.

This sort of thing carries on for the next 2/3 game turns and all the assault marines die marine, with about 4 necrons dropping. And lemartes loses a wound and another 3/4 from the other squad drops.
Stupid WBB . The necron lord also shows himself and charges the death company, and so does the other necron squad. My tactical squad finally does something and charges into the big battle in the middle of the board. Then a few turns later my tactical squad is gone except the veteran. And lemartes is down to 1 wound. My power fist smites the necron lord and I have gotten the necron count down to 8, 3 more till phase out. And it was 5th turn, so i rolled to see if there was another turn, yep!!
I drop 4 of his 'crons and he kills everything but my chaplain. He rolls his WBB rolls i need three fails, it looks grim .......6 (dam!) ..... 1 ...... 1..... ...... 1!!!!!


He went off in a mardy


What I learnt :
Never use a combat squad without transport to slow behind my jumpers.
Avoid charging a large unit without support.