So far, I've tried creating a new folder for VST plugins and filling it with the plugins I have from FL studio, and changing the source folder in Ableton to that folder, to no avail. Any suggestions? Also, I downloaded Max for Ableton Live but an unable to access it through Ableton. Any help for these two issues is much appreciated.
Method 1: Buy plugins as VST
Not all FL plugins will work on outside of FL. Cause they are FL only plugins. You have to purchase them from image line separately to use outside of FL. Go to Image line plugin page, check if it is available as VST, some available as Audio Unit too. You will see windows, apple logo next to the name, or VST icon in each plugins details.
Method 2: Rewire
Use Voicemeeter to digitally send audio from Ableton to FL, run FL Studio as a VST within Ableton; from there you can save the audio within FL, export WAV, and import into Ableton [OR you could setup an additional in/out within Voicemeeter and patch post audio back into Ableton (possible latency)]