in terms of dedicated fighter crafts the earliest options are the daredevil and buckaroo, both of which are roughly equal to the little bird and angry bird in terms of firepower and speed. for these you will need to research aerodynamics and necroparts recycling. the next step up is the tiger, unlocked by researching armored jetfighter, but even that only has 900 speed and can only mount weak ground weapons. when you're dealing with all this garbage and your best gun is a 14mm, keep an eye out for Gecko SAMs in the loot; those 20 damage rockets are the strongest raw damage available for ground weapons.
the next tier up from these ground vehicles and necroplanes is the aircars mentioned by delian unlocked by Contact: Car Thieves, all of which are fast but not particularly tough or killy. aircar-tier craft are good for bullying ground targets, slow aircraft, and other aircars, and they can take down excatavors and guild freighters but they will struggle against real UFOs. on roughly the same tier as the aircar/airspeeder is the faust (unlocked by contacts: blackmarch) and the piranha jetbike available as a bounty hunting prize. the faust is tougher than an aircar with 6 crew and a more defensible layout, while the piranha mounts 2 guns and goes quite fast.
once you choose a codex and unlock Shadowmasters you'll gain access to a variety of craft based on which codex you choose, all of which are servicable fighter-transports for the rest of the game. completing the Tiny Drill sequence of researching and manufacturing will also unlock a codex-specific flagship which is also good for the rest of the game. creating more conventional air-superiority fighters (ex Hunter-Killer and Predator) is unlocked by *Pirate Airforce* and Interceptor Assembly, both of which are firmly in the midgame range of techs.