There are a number of beginner videos on youtube, I recommend you go watch some when you have the time. Red Means Recording has a pretty good Let's Learn Eurorack series, Chris Meyer also has some beginner videos (although I think his main courses are behind a paywall) and Monorail Tech Talk has tons of interesting patch explanations once you're more familiar with the basic stuff.
But very briefly: Unlike a regular synth, a modular synth has all its basic components unconnected and you need to make your own connections using patch cables. Some jacks send out control voltage (CV), some send out audio in the most general sense the only difference is that CV is slow moving or static and audio voltages move at well...audio rates. Most input jacks will take either source, but some aren't "DC coupled" and will ignore CV (ie. sub-audio rate voltages).
More specifically, as to your rack:
-The top row is essentially a voice plus some effects. A modular oscillator just keeps going, try patching the outputs of your VCO2 (voltage controlled oscillator) to the Black Output to listen to the various waves it makes (it's recommended to attenuate the volume using the knobs first).
-After you know how the vco sounds, send its output to the filter (VCF) first before sending it to the output. Now you can cut off frequencies and add resonances to the base waves.
-After that, put the VCA between the filter and the output. Now you can't hear anything! (at least with the Bias or Level turned down). That's because a VCA lets you control the volume of the oscillator. Punch in a super basic sequence on the sequencer and patch the Gate or Trigger output to the Envelope Generator (EG) in the second row, and patch that to the VCA CV. Now every time the sequencer sends a gate, the EG generates an envelope that opens the VCA. Play with the EG's settings to get a snappy envelope or a rising pumping sound.
-Congrats now you have the most basic synth voice patch set up the way it usually works in hardware synths. Experiment from there. What happens if you send noise to the second input of the VCA? What happens if you send a saw wave from the Modulator the FM input of the oscillator. Send the voice through the DSP to add a reverb or delay? Also, VCAs aren't just for audio, you can send an LFO to a VCA then only open it occasionally with a sequencer to add bursts of modulation only at certain times etc. Try sending audio signals to inputs. Try different types of waveshaping available in this rack (FM, Ring Mod, PWM, AM) to find sounds you like. Etc.
A general tip would be to attenuate (restrict the level of) your modulations before sending them to an input, unless that input already has an attenuator of its own. Otherwise everything will sound way too extreme, usually modulating 10-30% of a parameter is plenty already. Also, listening is super important! Especially in the early stages. Just try patching different things and twisting knobs to get a feel for what's happening. I requires some patience and practice but after a while you should develop a sense for what's what, what sounds are possible and where you want to take this rig.