Open Rocket, first thing!
What kind of altimeters do you have? Get those apps.
Libre Office.
Firefox, with several add-ons: uBlock Origin (mandatory!), Bypass Paywalls Clean, Noscript.
Use Firefox to read and create PDFs, instead of suffering the bug of the week from Adobe. Also, Libre Office will read and edit(!) PDFs. Both will print anything to a PDF file.
VLC for videos
Wireshark for misc internet hacking, also records Bluetooth and USB interfaces.
Thunderbird for email. It also does chat. Has address book and calendar. I don't use the calendar or chat.
I don't like Putty for ssh. Much prefer a real Gnome terminal. Or, WSL, it's pretty nice these days. And has all the usual favorite command line stuff, vi, ping, traceroute, dig, netcat, etc.
Edit: I used to enjoy IrfanView. Haven't used it for a long time. I'm sure it's still great. Somehow I mope along with file explorer in Windows.
To avoid: everything McAfee and everything Norton!! They do not protect your system, they just slow it down and cause trouble. If your new machine came with either, try to uninstall it. Good luck. Windows Defender is quite good, keep it updated.