Well, there is a minimum expected level of gear. In short, if you can't solo to 71, then I'm unsure why anyone would want deadweight in their group.
Minimum gear and how to group climb is explained below
https://forums.d2jsp.org/topic.php?t=82759999&f=74Also the amount of climbs happening right now is pretty minimal so I don't think any guild fulfills your requirement either.
I'd work on the solo venture and would recommend a barb rather than mage as they're easier to play seeing they don't have Mana issues and higher defense.
Mage is certainly doable with the bonus of dealing more damage with similar gear, but have their drawbacks
Good luck!
Mostly this. Invest at least a marginal amount of fg, do a couple solo runs, join a group climb or 2 if you see them happening, you'll find a place to fit in.
Group climbs are pretty dead at that time atm tho, hopefully a reset soon will spice things up