early game tips

[Revalopod]

what is good early game tips? I've done about 20 missions, my favoured gun is upgraded a couple times, I bought a skill thing, I upgraded cooling a bit.
I barely earn any keys. Is there a good way to get more? I heard you can sell meat for keys at a restaurant but I haven't seen one.
What are the differences between the ships apart from different amount of slots? are some faster, or more powerful? Maybe multiple weapon slots? What would be a good first ship to buy to replace the starter? Or is the starter good?

[keynup]

Trading meat for keys will give you the biggest increase to keys.
Find missions you can win easy or give good keys and make them favourite, then you can repeat them every day. And if you have enough saved you can hang around the restaurant and sell the meat without moving.
Don't bother about ships until later or if you find an ability you like, I think the starter is the best to get keys, the others let you hold more special weapon or slots (lives, etc)
At the restaurant I hung around until I could get the best heat sink (that also needs a better reactor so I got the best)
Skills get you more keys, so get the best you can handle.

[Revalopod]

very helpful thank you :)