If you do a search, you'll find the answer to this one pretty easily. There are threads up at the top (marked in red) that are there to help you, and this Forum has a search function... use it.

Now that I'm done barking here's an answer, because lord knows I pester people around here a lot, too

First, go get a copy of the Freelancer SDK 1.3, if you haven't already.

Open the following file: newcharacter.ini (it's in the CHARACTERS folder). There, you'll see a listing that looks something like this:
<pre><font size=1 face=Courier>
[Pilot
nickname = trent
body = trent
comm = trent
voice = trent_voice
body.anim = Sc_MLBODY_STND_000LV_A_31
thumb = interface\intro\objects\MULTI_blackdragonmale.3db
comm.anim = Sc_comm_body_unfold_female, Sc_headCOM

[Package
nickname = ge_fighter
strid_name = 11051
strid_desc = 11551
ship = ge_fighter
loadout = MP_ge_fighter
money = 20000000

[Faction
nickname = new_player
rep_group = co_ic_grp
base = LI01_01_Base
Package = ge_fighter
Pilot = trent
</font></pre>

Simply change the two lines that say "ship = ge_fighter" and "loadout = MP_ge_fighter" to whatever is appropriate.

For example, if you want starting players to have a Liberty Freighter as the starting ship, then change the lines to "ship = li_freighter" and "loadout = co_li_freighter_loadout01".

IMPORTANT NOTE: let's say, for a minute, that you're really trying to learn how to mod, and not just how to have an easier time playing SP through. If you're working on a mod, then you don't want to give players the "co_li_freighter_loadout01", because (if you look in the loadouts.ini file, in the SHIPS folder) and look it up, you'll see that Loadout was clearly intended for the AI to use- among other things, it has "infinite_power" listed as the engine. This means that this freighter, when flown by a competant human player, will have one heck of a lot of firepower, because it'll never run out of energy for its weapons.

To fix this problem is actually pretty easy, but it requires doing some copy-and-paste (don't cut anything, or you'll hose yer game, unless you really know what you're doing, hehe):

1. Open up the file named Goods.ini (it's in the EQUIPMENT folder). This file contains the default Loadouts of all the ships you can buy. Later on, you can try to tweak this in various ways- a lot of modders have made ships available as a "package deal" that also includes whatever the modders thought would be cool for the ship to have in terms of guns, shields, and so on.

2. Do a search for the following line: "nickname = lfr_package". This is the "package" sold to players when they buy a Liberty Freighter normally. Obviously, this is probably what we'd want new players to start with, so we need to put this into the Loadouts.ini file. Let's copy everything from [Good down to the line break.

3. Open up Loadouts.ini, and do a search for "co_li_freighter_loadout01" again. Now let's write a new Loadout that we can assign to new players in MP. Since we copied the information that we needed in the previous step, we can just paste it below that Loadout (hit your Enter key to put another line break in there, so that you are sure to be editing the right block of text):

<pre><font size=1 face=Courier>
[Good
nickname = lfr_package
category = ship
hull = lfr_hull
addon = ge_lfr_engine_01, internal, 1
addon = li_freighter_power01, internal, 1
addon = ge_s_scanner_01, internal, 1
addon = ge_s_tractor_01, internal, 1
addon = contrail01, HpContrail01, 1
addon = contrail01, HpContrail02, 1
</font></pre>

Obviously, this isn't the same as the other entries in Loadouts.ini, but it looks really similar. To make it into a new Loadout, just change a few things, and you should end up with this:

<pre><font size=1 face=Courier>
[Good
nickname = Multiplayer_Starter_Ship
archetype = li_freighter
equip = ge_lfr_engine_01, internal, 1
equip = li_freighter_power01, internal, 1
equip = ge_s_scanner_01, internal, 1
equip = ge_s_tractor_01, internal, 1
equip = contrail01, HpContrail01, 1
equip = contrail01, HpContrail02, 1
</font></pre>

The "archetype" refers the ship's Hull, which in turn refers to the model. It also works with the Shiparch.ini's listing of the Hardpoints available on the ship, so that neither shop nor the larger game engine get confused about what objects should be attached to this ship, and what they do. Changing "addon" to "equip" basically just means that these things will already be mounted on the ship.

Now, go back to newcharacter.ini, and change the lines to this:

<pre><font size=1 face=Courier>
ship = li_freighter
loadout = Multiplayer_Starter_Ship
</font></pre>

... and that's all there is to it. Now your new players will get a free Liberty Freighter, that's equipped with just the basics, and whatever starting money you specify (that's in newcharacter.ini, too, if you didn't notice in the example above).

can this same method be used to change the startship and location in open SP???

Talking About Art Is Like Dancing About Architectur (David Bowie)