I cannot issue an assault order using the right click of my touch panel and then change to the left click because I don´t have a mouse, just the touch panel

Buy a mouse... problem solved!

The problem is I can´t, I´m in quarantine, cannot leave my ship. Do you understand now? Isn´t there a shorcut key???

How can issue an assault order with a plain touchpad?

I don't have this game, but if your mouse/touchpad keys don't work well you can enable Mouse Keys in the Mouse section of your System Settings.

Once you do that, use these keys:
Num Lock: Turn Mouse Keys on/off
Keypad 5: One click of Left/Right mouse key
Keypad +: Double click of Left Right mouse key
Keypad /: Change Keypad 5 between Left/Right mouse keys

Also, once enabled a small mouse icon will appear in your hidden icons on the taskbar which will show you if it's
on for left mouse key, on for right mouse key or off.

Lets face it. It's not a game made for a track pad. You could try bind those commands to the keyboard. Would still be seriously awkward.