How can I train my dog?

Im afraid because my dad doesnt like my dog and he threatened to give him away. I love my dog, hus name is oreo, cus hes black and has a little white on his throat, he is a chihuahua mixed with a labrador. Its kind of late for training cus he is 4 and a half years old. Im trying to teach him to be paper trained by getting rid of all sents and bying that liqiud at the store that smells like urin. First ill get rid of all scents he did it on, then pout newspaper at a certain spot and spray the urine liquid there, hoping he gos there. Tell me if that can work, i havent tried it yet. I also need to know how to train him in any other thing. how to sit, stay, and behave during a walk, u no, the normal dog stuff. I also want to enter him in one of those dog athletics things, i wanted him in the jack russel hurdle racing but hes not a jack russel, please tell me what event this chihuahua mix can do and how to train him for it, thanks to you all. And how to train him to behave and do normal dog tricks. thank you.