Buy European

(...) if Russia can't even win against Ukraine how would they ever fight against the EU, our army is both larger and much better equipped then Ukraine.

The problem is, the EU isn't united nearly enough to fight a war together. If, for instance, Russia attacks, it'll be mostly Poland, Lithuania, Latvia and Estonia defending. Maybe Romania too, and maybe with some support from the rest of the EU. As it stands right now, the EU is divided on many issues, with some countries (notably Hungary) intentionally sabotaging it from the inside.

Even if - and that's a big if - all or at least most of EU member states can come to agreement and cooperate in a conflict, our militaries aren't very well prepared to work together. This would require years of cross-border military drills between all of the member states. Especially considering the fact that the vast majority of all EU soldiers have never seen any real combat. Russia may be losing a lot of soldiers in Ukraine. But those who survive become extremely valuable assets for the military, since real world combat experience is infinitely more useful than textbooks or casual training exercises.

if Russia can't even win against Ukraine how would they ever fight against the EU, our army is both larger and much better equipped then Ukraine

Yes, if Russia invades EU then all gloves are off. But in the more immediate and near term this is about military production, which Russia is in full production capacity while the West as a whole is kind of just tip toeing. The former is already outproducing the latter in artillery munitions by a wide margin. The EU produces even less than the US in military. Even though the EU became the biggest aid sponsor of Ukraine, much of that aid is non-lethal forms like finances, food and logistics. The US still provide the biggest military help to Ukraine.

Even if there is a war between EU and Russia, fact of the matter is that Russia already has the initial military production advantage over the EU, because the EU downsized and underestimated Russia's plan of aggression for years.

I think what the EU-US trade deal was about is outsourcing the military production to US, while the EU ramps up their own. After all, the key message from that deal is that the EU will invest in US military production.