Advent have arguably the weakest civilian technology tree when you only have two labs (although easy access to culture is nice, any map small enough to make that dangerous is too small to pursue civilian techs early on). For me, I don't even touch the Advent civilian tech tree until I'm ready to put up three labs, then I go straight for trade ports.
Now, you have to remember that light frigates beat carriers, carriers beat long range frigates, and long range frigates beat light frigates. If you build any one unit to the exclusion of the other two, you have a gaping weakness that your opponent can exploit. Build disciples and long range frigates kill you; build carriers and light frigates kill you; build illuminators and carriers kill you; there's no getting away from it! There is a holy grail unit that can deal with this conundrum: it's called a scout. Look at what your opponent is doing and structure your own fleet accordingly. If you see three labs go up and virtually no units, anticipate enemy carriers and buff up on disciples. If you see long range frigates coming out, quickly get your own carriers up to speed.
Against the AI, you can almost never go wrong with just putting up three labs at the start of the game and researching illuminators, because it will predictably build light frigates for the early part of the game.
