Can anyone tell me good oracle spreads to know the guidance in relationship 

It really depends on the deck. 
I usually shuffle and pull however many I’m being guided to pull. It’s never a set number. Just go with how you feel. 

I wanted to share here a spread that I found useful because it's... short and to the point, and doesn't focus only on romantic relationships. It was taken from the companion book of Kim Krans' Wild Unknown Animal Spirit oracle, but I have used it with other oracles as well!

.....4.....

1...5...2

.....3.....

1. You

2. The other person

3. The shadow dynamic

4. The illuminated dynamic

5. Advice

Personally (this is not in the book), I choose to interpret the shadow dynamic as that which is lacking or not developing naturally and the illuminated dynamic as that which flows naturally in the relationship. But I also think the shadow dynamic and represent an unconscious dynamic between the people involved, while the illuminate dynamic can represent the visible/obvious dynamic. You will have to try and see what works best for you.