As with all 4X games, the direction in playing is up to you. A lot of people fall into the "too much choice, not enough focus" problem which was(is) prevalent in the Civilization series. Going into the game with a clear idea of which winning condition you want to pursue helps you pick not only your race, but also your starting tech choices and settling strategy (or vice versa, which race you pick helps you narrow down the winning conditions you choose to pursue). Not all plan's survive contact with the enemy though, so those plan's may change mid game depending on the situation in the universe but at least you have a relatively focused goal at the beginning.
For example, my latest game I chose to go for a Tech victory as I have not done one yet. So my initial strategy was to settle and secure my own little corner of the map, focus 2 or 3 planets on production/coin (they can share that role - I don't need vast amount's of ships to conquer the galaxy, just enough to defend myself) and the rest on research with just enough production to get the research building upgrades in a reasonable amount of time. Tech choice wise, a heavy focus on research and economy techs was the choice, with just enough military techs to keep my fleets current for defense. As my fleets will only ever be defending home territory, the entire life support and invasion lines are useless so I don't need to bother with them.
Try picking a winning goal first and then focusing your builds/tech/fleets on that goal and you should have a bit more direction in your game-play.
Another suggestion I have, in regards to the ship designer, is to filter by core and obsolete every single design as it becomes available. The generic ships are, in general, terrible and shouldn't be built. Design your ships based upon what you need RIGHT NOW. If you need to build a starbase 15 tiles away to claim some resources that are about to be stolen by an AI, build a constructor with 4 or 5 engines to get it there asap. If you are building economic starbases in the back of your territory then you probably only need 1 engine, maybe 0 and you certainly don't need life support. If you need to clean up pirates and they are using beam weapons and shields, design a small/medium ship with missles and engines. You will pop them before they fire at you. What I am trying to say is, tailor make your ships like you do your tech choices. There is no reason to incorporate items on your ships that you do not need, like life support and sensors if it is operating in your home territory anyway.