"Love for rent" could mean two things:
That love is available for rent.
The love for renting things.
Am I right with my interpretation? Which interpretation is more likely to be chosen?
You cannot take phrases in isolation and ask what they mean. That said, your first attempt is OK. The noun "love" is modified by the phrase "for rent" just like "bicycle for sale".
However, to express the idea that one loves to rent (whatever that might mean -- rather than buy?) you'd need the gerund or the infinitive
He has a love for renting.
He loves to rent.
If we stretch it, "love for rent" might refer to a landlord's delight in receiving the money.
His love for rent was far greater than his love for building maintenance.
for is grammatical there but most often you'd hear of instead, "love of rent", as "love for" usually expresses the idea of what love one has to give, and that sense runs counter to a greedy landlord's receiving rent. But "love for" can be understood to refer to a predilection.