Space is huge beyond meaningful logical comprehension. We know the numbers as good as a 1st class kid learns to count 1-10, as the kid can only imagine what is after 10, how far it goes and even what those symbols will later on help him with.
Within space points of interest are scarce within that volume and valuable resources even more scarce. Multiplied by the space itself though, there are ... countless! But engaging the volume of space plus the time that is essential to describe space time, how can conflict arise? War between different species, because as long as we speak for civil war of 1 species alone, this war will start and end at the home planet. If and when humans manage to create a new colony comparable to earth to population, then we instantly speak for different species. It is the vast space itself that defines that:
A meteor strikes Mars and Mars is now habitable, a brand new and virgin Earth. We go there and after 200 years Mars is a second Earth. Somewhat in better condition due to higher respect to the environment. So far so good. We know have Earthians and Marsians, because people finally understood that only unity will get them further and make them happier. Now Earth miss resource A and Mars miss resource B, while Earth has plenty of B and Mars has plenty of A. Obviously they trade. Not rage war with battleships to gain orbital control and then rage war with land and atmosphere vehicles to finally seize the opposing planet. The cost is forbidding. You simply trade the resource. Even the cost of transfer will be notable, but, nevertheless, far cheaper that war. Ok, and now the hard part. Both Eartians and Marsians miss resource C. What they do? Most likely they do not know where it is. Even if one found it, the other will also found it. A finders-keepers logic will not help. Most likely they unite efforts, search the entire system for the resource and, when find it, organize their safe extraction and transfer, so both share it. Why? Because it is cheaper. It is so deadly cheaper that with the cost of a space war they would find 5 C resource sources, and other 5 of resources D, E and F that they will come to miss in the future after shortage of C and, the rest of the funds will go for FTL travel research. :)
Example 2: Two races meet at the edge of their exploration bubbles. We obviously talk for available star travel tech level, minimum. While stories rage war, intelligent approach is different: First comes trade agreement, then exchanging exploration data. Those 2 things alone can be as valuable for both as multiple times their annual growth. Because both will be available to trade their abundant resources for rare ones (for them when match) plus both will be able to extract resources they miss, located at other space because the others simply so not need. Not to mention combined efforts. Actually is not really different than the Earth-Mars story. And why should be?
Combat fleets now. What for? Attacking who? Your own kind at another colony? Or an unknown 'enemy'? There would be some prototype warships, with the best of tech on, but not at a large scale. Again, space itself, protects. If the 'others' attack you, you know about it years before it happens. You should have plenty of time to produce equal or more numerous combat fleet on defensive position at your point of interest, before enemy actually arrives and with less energy than the one spent by your enemy to sent the fleet.
So yes. There would be top tech combat ships, from fighters to battleships and carriers, orbital defense stations, planetary defenses and all that stuff, but i can hardly imagine conflict possible, unless some species are ... not exactly intelligent or been warlike by DNA. Hard to advance to tech that way though.