If I happen to be an infantryman stationed in France when hostilities break out, is there a realistic chance I survive the entire war, or will I probably just be a victim of attrition?
I'm asking about infantry because I assume everyone's cavalry is completely wiped out.
Subquestion: Are the odds drastically different for any of the major powers?
^ these answers I've given should help
France called up 8.3 million men, including colonials in WWI, of which 4.2 million were casualties, 1.1 million killed. They suffered 454 000 casualties between August and November 1914, with 27 000 soldiers killed on August 22nd, 1914 alone. Losses were still high in 1915, but by 1916 French losses, though still high over all, were at a much lesser rate (ex. 378 000 casualties at Verdun over the course of a year, 204 000 casualties at the Somme over 141 days). Losses spiked with the Nivelle offensive in April-May, but losses were less than 200 000. They spiked again in 1918, partly from influenza, but also from a shift to semi-mobile/mobile 'open' warfare. Statistically, A French soldier in 1914 had a 50% chance of being a casualty, and that is the same for the whole war, with a 1 in 8 chance of death.
As to your subquestion, the BEF and the Austro-Hungarian Army were decimated by losses in 1914, the BEF because of it's small size in relation to the intensity of combat, the Austro-Hungarians due to poor leadership, equipment and tactics.
As a final note, everyone's cavalry was NOT in fact, completely wiped out. French cavalry gave valuable service during the great retreat at the end of august and in the Race to the Sea (one cavalry general joined the ranks of 47 French Generals killed in the war, in 1914). They saw some combat during Second Artois, and more on the Flaucourt Plateau during the Somme Campaign. They saw extensive fighting in 1918, on the Western Front and at Salonika. The idea of Cavalry being 'useless' in WWI, and in Modern War in general, is highly exaggerated.