This is part of why the 2018 Tides is a little more useful in a smaller system - the addition of attenuverters and the extension of the level control to cover a few different functions helps cut out some other modules for certain tasks. For example, in it's audio mode, the level control can act as a pseudo-vca (like the original, but it only affects the bipolar output).
You'll still need a mixer and a VCA for things like chords mode, or gating CV's. As for mixing multiple outputs, in the default audio mode, you git a bipolar, unipolar, pulse, and sub output. Generally, I find myself only using two of those, maybe three (I rarely use audio output as an audio signal on its own - but it's really useful as the modulation frequency for AM).
I've found Tides to be extremely compatible with pretty much anything. If you're starting out, and you don't want to expand too quickly, Maths acts as a great source of modulation and mixing, though you'll probably still want a simple VCA to play around with as well. And if you're getting a second oscillator at some point, checkout something like Blinds - the sine output of Tides is fantastic for ring modulation, and that ability to invert the phase of a modulation source is useful in some circumstances.