I hate to say it, but u have some major flaws in ur team. I will need some time to explain them...
1. Venusaur : U have given 3 moves of the same type. Sure they provide STAB, but u should include a variety of other options. Stick with Earthquake. If you want to use Solarbeam, teach it Sunny Day, which allows no charge for Solarbeam. And at last, put Sludge Bomb, which provides STAB.
2. Kadabra ( evolve it! ) : Again the same. U have put in 3 attacks with the same type. Well, u can keep Psychic and Recover. Future Sight is good as it has a neutral type, but i wouldnt be using it ( u can if u want ). And level up your Alakazam ( Kadabra ) a little more if u want it to be a good sweeper in ur team.
3. Nidoqueen : Superpower is a good hit, but be careful as it lowers ATK and DEF after use. Then u can go for Sludge Bomb and Earthquake which will provide a good STAB. For the last move, teach it a strong move of ur choice. But as Nidoqueen is good at physicality, u should stick with physical attacks rather than going special.
Ok, for ur other team mates, I am lost. U just cant go on challenge the E4 with wild Pokemons. Tell u what, heres an easy wasy to beat em.
The first E4 is Loreille, TYPE : Water / Ice. Basically electric and fighting should work wonders. So, rasie a good electric and fighter ( I suggest Primeape and Raichu )
The second is Bruno, all fighting types except Onix. Defeating Onix will be easy with Venusaur, and for the fighters, take a Gengar with Psychic. Your Alakazam will work too, but it will get hit by the fighter's physical hits.
The third is Agatha. Ghost / Poison. Here is where ur Alakazam will shine. Throw some Psychics and u'll hit a home run!
The last E4 is Lance, with Dragons, Aerodactyl and Gyarados. Take down Gyarados with an electric attack, and the dragons will have hard times with high leveled ice attacks ( Teach a good ice Pokemon Ice Beam. If u want, Articuno will work awesome )
Finally your rival, whos ur champ. He will have :
Pidgeot ( electric attacks will beat it)
Exeggutor ( throw fire attacks, or use Articuno here too)
Gyarados ( electricity again )
Arcanine ( counter with water types )
Alakazam ( darks are best here, but u can try with Magneton, cause there arent much other pokemon that can resist both of its Psychic and Shadow Ball)
Charizard ( as u took Venusaur) ( ok, take a bulky water type)
If u have problems understanding and need further help, ask away
