Minecraft/First Day
Sweet,playing survival?Good luck on Hard mode!
What should you first do?
Collect as many logs from any tree,the closer,the faster.Then turn it into planks by your inventory and then into a crafting table,so you could create weapons for the night.
Enough planks for now,then...?
Create either a 4×4×3 (l.w.h)(larger if you want,but smaller is faster!)base or if you like daring the wild,create swords and pickaxes (2 average here) and dig up stone for cobblestone to create stone tools,which are better.
What about food?
Create swords and kill pigs,cows and ckickens for meat,best if you mainly kill sheep for wool for now for a bed,unless if you luckily find a village while exploring,then take food from there.
Recommendations
A Minecraft day lasts for 20 minutes,so best if you collect 20 to 40 logs(that is quite alot!) and build a 9×9×3 house,for safety(maybe a house for hard mode,zombies can break your wooden door and kill you!,but only if you were being chased and was seen entering the abode,unless if you are lucky enough to live another day safely)