Yes, of course. Any “modular” synthesizer lets you do this. In modular language, the LFO would have an output, and the other module (let’s say it’s a filter) would have an input (let’s say it’s the cutoff frequency modulation input). You “patch” the LFO output to the filter input and voila.
This metaphor, however, is probably different from what you are used to in your DAW or VST synthesizer plugin.
If you continue your interest in VCV, you will want to learn the fundamentals. If you search this forum you will find many, many many resources that will be useful.
VCO-1’s V/OCT input is the pitch input. (That’s a standard convention in modular, invented I think by Bob Moog, where voltage changes pitch and 1 volt means one octave change, hence V/OCT). So if you put CV into that input, it covers the function of both the FREQ and FINE knobs.
If you want to turn knobs (flip switches, etc.) with CV, especially when there’s no input available (as with the VCO-1 ANLG/DIGI and HARD/SOFT switches), @computerscare gave you a good recommendation. CV-Map is the full version (edit: here’s the manual, which is great; you’ll see that the library descriptions are often pretty minimal but the little “User manual” link is gold):
You can also do this with MIDI with
or the more advanced Stoermelder MIDI-CAT:
A friendly meta-comment: it sounds like you’re having a strong early engagement with Rack, and that’s great–I look forward to hearing the music you produce!–but I’ll echo what others have said that you may want to start with browsing existing posts on the forum, working through some tutorials, etc. Omri Cohen on Youtube is a great place to start. That way the forum will be a fresh resource for help you really need and that’s not already available elsewhere
Instead of asking all these questions and expecting to be spoon-fed answers (without ever a thank you as far as I can see), please take some time yourself to learn the basics. There are some excellent VCV tutorials on Youtube that will get you started and the thread linked below contains some great resources.
It’s fine to ask specific questions when you run into a problem, and the community here are very helpful, but you do need to put in some effort of your own to learn rather than just spam the forum with endless basic questions.