1)"game goes slow y dont know why help pliss"
I had the same problem, it took me a while to figure it out, but this is what i changed;
Load the rom first, go to your graphic plugin, then
In the "CURRENT GAME OPTIONS" tab of the plugin you must change the whatever you have for the "N64 FRAME BUFFER" and change it into "NONE".
2)"I cannot see the title screen"
i had this same issue in the titlescreen, but this also applies to when playing some songs, when fighting a boss in a temple(the boss intro only) and i think their might be more. but this is what i changed:
from the same screen as before "CURRENT GAME OPTIONS", where it says RENDERING TO TEXTURE", by default this is turned off, you must any of them thats not default and none, i chose "HIDE RENDER-TO-TEXTURE EFFECTS"
This helped me, hopefully for you too.