GamerGlutton: ...As there was no difficulty indicator for each mission, I chose one that was apparently not the right mission for a newbie. I got destroyed by one Retro preeeetty fast as he seemed to have meson blasters and lasers!
This is my first space sim so I am having a lot of trouble and the manual isn't exactly helpful...
First of all don't "play chicken" with hostile who has more firepower then you. Even without afterburners you should make "evasive maneuvers" by (slightly) changing you course to avoid enemy's fire(-balls/-bolts). Don't make big changes of your course (more then 45-90 degrees) because you'll lose speed.
When hostile ship isn't flying straight to/from you (you can see his sideboard) then try to shoot with a little advance. Later you can buy better radars with IFF but they cost a lot of money (third category, first column from right). IMO next radar for player is Hunter 6i (just in the center).
I prefer guns than missiles so my choice for start is:
1) sell missile launcher,
2) buy second laser gun,
3) buy tungsten first (iron as second) at mining bases; don't take any radioactive; gems are very expensive so you'll make more money per unit with cheaper goods,
4) buy wood first (liqueur/luxury food as second; later pets too) at agricultural planet (Helen),
5) if you didn't played Priv before then don't take more than one mission at once,
6) always check who will be your opponent (avoid Kilrathi!); if mission description hasn't clearly described ships' faction then avoid this,
7) you can do 3 the same missions at once (e.g. 3x patrol the same nav-point in Troy) but you'll face three time more enemies (sometimes in the same nav-point if you'll have bad luck).
My upgrade path for Tarsus:
afterburner -> tungsten armor -> cargo expansion -> engine upgrade lv1 -> two Meson Blasters -> repair droid -> ECM Package lv3 -> 1x missile launcher with 10 FoF (no delay for tracking) -> Tracktor Beam -> All Nav Maps (at once; you don't need it to fly but at nav comp you will see what you've visited only) -> Jump Drive.
If you prefer to be mercenary then wait and collect money for Centurion (200k cr). If you'll buy Galaxy (150k cr) then you'll lose half of money when selling it. I don't recommend Orion - it's slow and easy to hit ("big butt").
Until you'll have fully upgraded Tarsus don't make missions outside of Troy system. Until you'll have something better than Tarsus avoid system with Pirates ("north-west") and Kilrathies ("north-east").
Try to make all three mission at once because you can loose some after landing.
Missions from Guilds are better payed than from computer but you must pay registration fee.
Watch for jump fuel level! You have only 6 jumps and not all system have bases.
Save often. Make at least two saves: 1st after landing, 2nd after taking mission(-s).
If you're playing using joystick or keyboard and you have problem with too big "dead zone" (it's hard to aim hostile ships for good hit) then try mouse (like I did).
If your ships was hit and you can't escape then try to "show them" other side with full shields/armor.
If you'll fight with two or more hostiles then don't focus too long on one target because other ships will bite your ass really hard.
If you have Tractor Beam and you'll take mission against pirates then make sure you'll have some space in cargo hold because they sometimes drop some valuable cargo (but avoid contraband).
If you want to fly a little longer with Tarsus and you have enough money then buy Tachyon Cannons. They'll use the same energy like Meson Blaster but will do c.a. 50% more damage. IMHO it's the best weapon in the game if you're good shooter (the best ratio "energy/damage").
Read manual to the end. Especially "Survival Tips".