If it’s been untouched since 2019, all that could go wrong has already happened. Worry about it when you get it going, or you’ll just end up doing the same thing twice. Doing stuff to it now, without a few proper runs to eliminate humidity before storing it again will hurt more than do good.
Oil does get acidic from contact with combustion and fuel residues, humidity and time, hence it’s usually advised to change the oil yearly if you care about the engine and it gets little use. If the 10 or 15 Euros it costs to buy some cheap oil to put in it while not running is too much of an expense just let it be and do it when getting it to go again.