Marlin 2.0 noob

I want to run marlin 2.0 on my a20m but it seems to be flaky or too much is trying to be done in the background. It will load up and run it but sometimes it will hang up and not respond or will have trouble reading sd card or also hang up if i tell it to switch to the other extruder or to mix the colors..if anyone can help me get this to work as i like the features it had in it..

I used the one for the a20m inside the confi/examples folder of marlin 2.0 cause i dont know how setup marlin for printers...

Tried to upload the marlin that came on it but file to big

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lol ok yea guess that would make since...was not thinking.. i so confused forgot where i was at