Installed the latest version of Jupgrade and installed cbjuice2 (latest version) in the jupgrade website. I installed the latest version of CBjuice2 in the new site. Both sites have latest version of CB.
The fields and the avatars are not transferring. I'm getting this after running it.

CB Version =1.8
CBJ2_HEADER_VARIABLES are
Array ( [0] => name [1] => username [2] => email [3] => password [4] => block [5] => sendEmail [6] => registerDate [7] => lastvisitDate [8] => activation [9] => params [10] => user_id [11] => firstname [12] => middlename [13] => lastname [14] => hits [15] => message_last_sent [16] => message_number_sent [17] => avatar [18] => avatarapproved [19] => approved [20] => confirmed [21] => lastupdatedate [22] => registeripaddr [23] => cbactivation [24] => banned [25] => banneddate [26] => unbanneddate [27] => bannedby [28] => unbannedby [29] => bannedreason [30] => acceptedterms [31] => cb_clubname [32] => cb_clubaddressstreet [33] => cb_clubaddresscity [34] => cb_clubaddressstate [35] => cb_clubaddresszipcode [36] => cb_clubphone [37] => cb_clubemail [38] => cb_clubwebsite [39] => cb_clubdescription [40] => cb_usercity [41] => cb_userstate [42] => cb_accountlevels [43] => cb_coach [44] => cb_clubcountry [45] => cb_clubaffiliation [46] => cb_usercountry [47] => cb_newsletter [48] => cb_region [49] => cb_snatch [50] => cb_weightclass [51] => cb_doublejerk [52] => cb_singlecleanandjerk [53] => cb_doublecleanandjerk [54] => cb_rankingofficer [55] => usertype )

cb_clubname is not valid

cb_clubaddressstreet is not valid

cb_clubaddresscity is not valid

cb_clubaddressstate is not valid

cb_clubaddresszipcode is not valid

cb_clubphone is not valid

cb_clubemail is not valid

cb_clubwebsite is not valid

cb_clubdescription is not valid

cb_usercity is not valid

cb_userstate is not valid

cb_accountlevels is not valid

cb_coach is not valid

cb_clubcountry is not valid

cb_usercountry is not valid

cb_newsletter is not valid

cb_region is not valid

cb_snatch is not valid

cb_weightclass is not valid

cb_doublejerk is not valid

cb_singlecleanandjerk is not valid

cb_doublecleanandjerk is not valid

cb_rankingofficer is not valid

Terminating because of undefined header variables

Jupgrade does NOT move the cb field definitions or any part of CB. You must do that the hard way moving the cb tables.

I know how to export and import tables through phpadmin but I wouldn't know what to move.
which tables should I move? What about the avatars?
thank you!

Look in the main CB forums about upgrading. You can get advice there. If you are not familiar with CB, I would read the documentation and study the file structure of your site. You also have to worry about moving plugins etc. It takes a bit of planning.