People at r/goodyearwelt recommend Bick 4 as a conditioner and Lexol as a Cleaner for beginners. They don't change the color of the leather and are really hard to screw up.
There are other great options like Venetian Leather Balm or Saphir Médaille d'Or Renovateur for conditioning. These are more expensive than Bick 4 and may change de color a bit. However, they are more nourishing than Bick 4.
A stronger option for cleaning your shoes would be using a saddle soap. The most used brand is Fiebing's Saddle Soap, but there are many other great brands.
These options are way better than Leather Honey Cleaner and Conditioner. I don't know if they ship to your country, but these are the most recommended brands at all the boots subreddits I am a member.
If you want to waterproof it, you can use Saphir Médaille d'Or Super Invulner or Tarrago Nano Protector, but I don't think it would be necessary, since these are sneakers and not boots that would be used for walking on water.
I am not a cobbler, but Steve from Bedo's Leatherworks, one of the most renowned cobblers in the US, uses Bick 4 to condition Shell Cordovan, even when the shoes are severely worn. You can see this in his videos.
Thats in good shape and looks great. Not alot of the early 90's leather had real armor, most had an extra slab of leather sewn on and some type of foam in the liner. I would give it a good leather treatment, I use this:
https://www.amazon.com/gp/product/B001CS8G3C/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&psc=1
Leather. Bick 4.