Present simple/progressive for future events

Hi,

Which of the sentences below are correct, please?

1- I meet my friends later/soon.

2- I'm meeting my friends later/soon.

3- We're traveling to England next summer.

4- We travel to England next summer.

To me, #3, #4 are correct due to expressing a specific point of time in the future. (next summer)

I'm rather sure that #1 is incorrect because of the above reason.

#2 based on a timetable, might also be correct, I suppose.

Please offer an answer for them considering both timetable and personal actions.