Thunderbolt and USB logo on screen I was trying to refresh my MacBook Air because I had just purchased a veikk A15 pen tablet and was trying to connect it to my MacBook Air. The instructions told me to refresh my MacBook Air and so I did. But then a USB and thunderbolt logo appears on my screen and won’t load my computer. This MacBook Air as no thunderbolt or USB port.

What has happened to my Mac?
These symbols are displayed when a Mac boots into target disk mode. Usually you activate it by pressing T at startup (different startup key combinations). Another option is to go into settings → startup disk → target disk mode.
You can simply restart your machine and it should boot normal. If it does not, disconnect all peripherals (mice, keyboards,...) and try again.
Target disk mode makes your internal hard-drive accessible to connected Macs via Thunderbolt/FireWire. Read more about target disk mode here or here.

If this still boots into target disk mode, then your T is broken and continuously sending a pressed state to your MBA (MacBookAir) which can only be solved by repair.

Note: I assume by refresh you mean reboot.