Canon eos 2000d options and help please

[Elp]

I believe pixinsight only works for astro images. There's some free data out there you can find to practice on, or just take photos of stars or open clusters as you can keep exposures short and stack them, you won't reveal faint nebulosity on many open star clusters (M45 Pleiades is a common exception) but you can learn the workflow. Siril is free.

Camera settings depend on your local LP levels, you can't ramp ISO up too high if it's around but note ISO is only an image amplifier, it doesn't cheat the laws of physics and make your camera suck up photons faster. I found with my 600D I usually used iso 1600 or so give or take either side of that figure. Exposure length also depends on LP levels but also imaging without stars trailing. With a 135mm and a fixed tripod you'll be limited.

Note focusing a SY135 is very sensitive, you need to have a very deft touch when fine focusing. Not sure if you have such a mode on your camera but focus magnification helps massively. Without it all I did was adjust focus, take a short preview, zoom in, repeat.

[Vroobel]

What about a Bahtinov mask? It should be quite popular for the Samyang 135mm. 

[Bivanus]

Hello @LunarRob here's some food for thought:

Hardware: Astrodymium Ring System for Rokinon / Samyang 135mm F2 Lens: Guidescop - this is only one of several kits dedicated to this type of lens, some of them also have realy pro-sumer options for motorised focusers and such I use a Canon zoom 18-135mm lens instead and put toghether my own little rig that I rather quickly upgraded to an astrocamera with an EOS lens to M48 adapter, atached a picture of the latest iteration 

Software: BackyardEOS - O'Telescope (otelescope.com)- I used it sporadically until I've got the EQ6 mount and went the way of the NINA 😅 but I will certainly still make use of it at some point since in my personal opinion it hits the spot for EOS astrophotography ( like all things, practice is required , and thus time...lack time being the scurge of our times ! )