Here are the completed sentences with the verbs in the correct tense (Present Perfect Continuous or Present Perfect Simple):
A
... I'm planning to buy a new house. I 1) ...'ve been looking... (look) for one for two months now. So far I 2) I've looked (look) at ten houses, but I 3) haven't found (not/find) one I liked.
B
... My Spanish lessons are going very well. I 1) I've been learning (learn) Spanish for five months now and I love it. I 2) I've already learned (already/learn) a lot.
C
... John 1) has been (be) very busy recently. He 2) has painted (paint) the living-room and the bedrooms, but he 3) hasn't started (not/ start) painting the kitchen yet.