im starting a campaign with an Orc army at 500 pts.

I am realy fond of the fanatics,, squig manglers, arachnork spiders, lobers, and grimgore iron hide with his imortall black orcs

any advice on how I should build my army, every 2 weeks were adding 200 pts ending at 1500 pts.

I can change the army list after every battle so I was wondering how I could optimize each stage progression with the use of these models. (I dont have to stick to these but I'd prefer to build around them)
and Id like 3 squads of night goblins with 2 fanatics a peace and 3 in the 3rd squad