(my native language dont are english because this my english is not so good) I dont have money for original Minecraft (im brazil costs 150R$), but i want to do speedruns.

yes u can speedrun it but u are not allowed to submit it to the official leaderboards

if i don't have record software, how do i get my speedrun checked and in the laderboard ?

i guess you can use Minecraft no premium, is exactly the same for 1 player lol, apart of that you cant use any strange diferent remake btw how many is 150R$