i am disappointed to multiclass into a cleric. i have a druid in my team, a dwarf fighter, i am a human fighter (5)/cleric (2).
but i can only memorize/cast spells level 0.
why on earth?

Just a guess... Because your Wisdom score is under 11?

right, sir! eh eh eh going to find a ring to fix it.
many thanks a lot.

Keep in mind that you will need a Wisdom score of 10 + spell level to cast a spell of that level. So to memorize and cast a level 4 spell, you need Wisdom of 14. And so on. Maybe Cleric wasn't the best career choice there.

that is what i fear. but i am a long way to roll it back now.
thanks

I guess you'll need to start dropping any and all stat points into wisdom, and find whatever items you can to boost this stat! Or, ditch the cleric idea :/

This is why you really need to sort of plan out your character before hand in D&D.