Basically, choose the car you are most comfortable using. If it's Alfa Romeo, choose it. If it's Subaru, choose it.
You may like the Lexus GR.3 and the Ferrari GR.4. Your choice may be based on which tracks you like to drive those cars on. Looking at the season, could be you prefer driving the GR.4 at majority of the tracks.
Check the FIA thread, if you want to pick a random brand or popular brand. In the end, just pick a brand and see how you go. Good luck.