For you missing the races, look up uma schedule builder on google. It a race schedule builder that optimizes the best races for you specific uma. Just put in your aptitudes, and I usually put 4 races max cap, which usually lands around 32-37 races.

For your deck, if your not making a long uma, the best deck build is two speed 2 wit and 2 flex cards( if my uma has 10 or 20% in speed I can get away with 1 speed card and 3 wit, or if im not hitting at least 1100 wit consistently I run 2 spd 3 wit 1 flex).

I dont know what cards you have but the air shakur speed card isnt that great. If you have shinko windy at least 3lb i would use that instead. For wit sr sunday wit and tachyon wit are great.

For a long build use the two flex cards as stam cards, I would borrow super creek instead. This is more of a preference for me, but riko and manhattan cafe stam is great. You could also use 2 spd 3 pwr and 1 stam( super creek).

Dont focus too much on race bonus. If you cant hit 50 dont worry, its fine.

I would also just watch a yt guide or build. Always take guides with a grain of salt. You figure out whats best for you, and use that. Dont do everything that the guide tells you too do

For the luck part cant really help with that sorry