I´m not sure in some levels to what is bether buy, because I like decorate my restorant but I tink I need other stuffs like a coffe machine or something, I realli want to know what you recomend me? se you leatter¡

Hello, susicute and welcome to PF forums.
 
I always buy the machine upgrades first and the decorations if any money is left after. 
 
I normally upgrade these things first before decorating.  Grandma's table, Grandma's speed.  Flo's speed,  jukebox, new ovens, Chilli sauce, faster ovens, faster jukebox, coffee machine. 
 
Then decorate.  That's just me though, you may find it easier to decorate in between upgrading machines.
 
I hope you find the right things that suits you best for your gameplay.
 
Good luck

Buy anything that's faster first. You'll need it to make the score. also the bigger table for granny. Decorate last. It won't help you with points.