Help with Japanese Kogal language

For my linguistics class at university, we have to analyse the following statements:

1.) 今日の昼、ヨシらない？

2.) 後輩にごちってあげた。


Now, the analysis would not be a problem if I knew what the underlined parts mean exactly.

I've been searching any site, any dictionary I could think of, but couldn't find anything.

Would anybody here be able to help me?