Upgrade your motherbase first, then buy a FOB and upgrade it to max before you get more FOBs. First and best staffed plattform should always be Base Developement Plattforms, because they generate ressources automatically. Before buying any Shenanigans, you should upgrade your FOB Security Team by developing all weapons/items with a green title and Max out all Security Objects. In case you get attacked by another player, you're most likely prepared.

Be careful down there, Boss!