Welcome! It's daunting at first and I made a lot of mistakes along the way which resulted in overspending.
First, what kind of sound do you want to make? An acid setup would be vastly different from ambient, etc. Do you want percussion or just a bass machine? Finding some youtube artists you like and studying their setups can help with this.
Second, download VCV Rack and start testing modules. All of the Mutable Instruments modules are in there, as well as a bunch from many other manufacturers. If you find a module in VCV rack that doesn't exactly exist in real life, there's usually a close match (and vice versa). Omri Cohen on YT is a great resource for rigging up real physical modules within VCV Rack in order to test them out BEFORE you buy. Look at the manuals, look at the youtube videos from the manufacturer, look at DivKid or MylarMelodies' reviews. There are a million resources out there to help you avoid buying modules you don't need.
Third, if you really think this is something you'll want to pursue, consider a bigger case. 84hp gets eaten up quick. It might be better to get a bigger case now and fill it up slowly over time than buy a small case and need to get a bigger one within a year. Also consider a pre-built rig like the Make Noise Shared System, one of the Erica Synths cases, or the ALM Shuttle Coupe. Yea, they're expensive, but they're great collections (Those Dreadbox Chromatic modules look pretty good, so you already have the right idea. ) There are also the Moog Mother 32 and DFAM semi-modulars that area really powerful without going broke too!
Good luck! Sorry I can't be more helpful, but those are some basic points you have to address yourself before getting module recommendations.