To start with open up your faction of choice and create a new fleet, in this fleet purchase one light cruiser, the cheapest you can and save your fleet. Next go to 1v1 skirmish and select necrons and fight them using your new fleet on easy difficulty. What this does is force the ai to build a necron fleet using 30% less points than your fleet, however if your playing admech that means you have a 99pt light cruiser which in turn means the ai needs to build a fleet with only 70pt. This is impossible. So two seconds after starting the game you will win by default since the ai couldn't afford a single line ship, and your reward for this action? The same amount of exp as beating a player with only two seconds of actual game time.

Enjoy.

Also here's a break down of exp required to level up;
1 -> 2 = 100 exp
2 -> 3 = 200 exp
3 -> 4 = 300 exp
4 -> 5 = 400 exp
5 -> 6 = 500 exp
6 -> 7 = 600 exp
7 -> 8 = 700 exp
8 -> 9 = 800 exp
9 -> 10 = 900 exp
10+ = 1000 exp

So getting to level 10 and unlocking everything takes 55 games, so depending on your load times this can take between 20-30 minutes.

A final note, I've been working on compiling every skill and upgrade in the game into a single guide, so you can look up what your faction has available and how many levels you need to grind out in order to make the build you want.

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1846463669