What are some devices (routers or switches) that have a vmdk available and commands or setup that are similar to Cisco's?

I'm doing a college project right now where I have to setup non-cisco devices in GNS3. The last project I had to use non-cisco devices it was a real struggle to find which command does what and it was like I'm learning cisco all over again. Some devices had me do a whole pre-configuration process just to get it ready to start being programmed. Which brand devices could I upload to gns3 that have easily available commands on the internet somewhere that are easy to compare with the equivalent cisco commands I already know? Routers are preferred, but I could route using switches and trunking too. Also it has to be something free.

Also I know reddit is often a little weird when it comes to questions about a homework project. Idk what else to say but this isn't an easy question I can find on google.