#1 first u will need to get some wood

#2 then u will need to make a crafting table and wooden pickaxe

#3 then dig under ground and get about 30 cobblestone

#4 go back up to ur carafting table and furnece and create a srone pickaxe

#5 then go and find a mine and search it for iron get 3 iron (also get some coal for smelting the iron in the future)
<-----iron ore

<-----coal ore

#6 go back up to ur crafting station and smelt ur iron with the coal u got

#7 use ur crafting table and make a iron pickaxe

#8 also make about 4 more stone pickaxes for mining cobble iron coal and lappis lazuli

#9 dig a stair case down to level 12 (u can check ur level by clicking f3 look at y and it will tell u ur level)

#10 when u et to level 12 dig a small room so u can move around a little

#11 there are many ways to find diamonds

#12 like make a gigantic room then keep making it bigger and BIGGER and BIGGER well u get the point

#13 or u could dig a 2 high 5 wide tunnel

there r many ways to find diamonds if u hav any ideas plz post a comment to me :D and plz do subscribe to me