Confidence is shot

I have been asked to photograph my niece's wedding later in the year - the first for me. I decided that I should practise some portrait photography. So on Sunday I arranged with my brother-in-law and his girlfriend to stroll thru the botanical gardens for a while....
What I had hoped would be a good experience has turned out to be a bit of a reality check for me I think. I took about 100 photos. Only 4 of them are OK. I knew I had a lot to learn, but I didn't think my shots would be this bad
I really struggled getting nice compositions/poses and nice exposures. So many variables to control....
What I was aiming for was nice shallow depth of field to give a blurry background with a bit of fill flash on the couple...
Here are my best ones....
75-300 f4.5-5.6 (@f.4.5, 80mm, A mode, SB600 with PJ direct)
50mm f1.8 MF
50mm f1.8 MF, manual exposure with SB600 + PJ direct
Kit lens @60mm f4.5, A mode, SB600 with PJ bounce
Any words of wisdom would be appreciated....
Cheers
Gecko
What I had hoped would be a good experience has turned out to be a bit of a reality check for me I think. I took about 100 photos. Only 4 of them are OK. I knew I had a lot to learn, but I didn't think my shots would be this bad

I really struggled getting nice compositions/poses and nice exposures. So many variables to control....
What I was aiming for was nice shallow depth of field to give a blurry background with a bit of fill flash on the couple...
Here are my best ones....

75-300 f4.5-5.6 (@f.4.5, 80mm, A mode, SB600 with PJ direct)

50mm f1.8 MF

50mm f1.8 MF, manual exposure with SB600 + PJ direct

Kit lens @60mm f4.5, A mode, SB600 with PJ bounce

Any words of wisdom would be appreciated....
Cheers
Gecko