Tropius is one of those underused pokemon it's typing of Grass and Flying isn't helping the issue any though it can be a serious tank if trained correctly and given moves that can take out it's weaknesses I'll get to more on those moves in a bit though


1st off lets start with abilities that you can find it with in the wild the most common one being Chlorophyll which boosts the pokemon's speed in sunshine, Solar Power which ups special attack in sunshine though decreases HP, and the hidden ability of Harvest which may create another berry after one is used up in battle (not sure if that means it is the same berry or not but ya a new berry might appear for it to use)


2nd thing you should knowz aboutz Tropius is all of the good TMs/HMs that it can learn I'm not going list them all just all of the good ones it can learn and yes it will span all generations

Cut, Fly, Strength, Flash, Rock Smash, Defog, Hidden Power, Hyper Beam, Solar Beam, Earthquake, Aerial Ace, Facade, Round, Steel Wing, Energy Ball, Giga Impact, Bulldoze, Grass Knot, Substitute, Secret Power, Nature Power, Return, Giga Drain, Bullet Seed, Silver Wind, and Natural Gift  if given both of the ground moves it can take out the fire and electric type pokemon it is weak to


3rd thing is all of the awesome movez it can learn while your training it either as the head of your team or with EXP Share yes these also will span all generations ^^

Razor Leaf, Gust, Sweet Scent (to use for finding pokemon), Stomp, Magical Leaf, Whirlwind (to force your opponent to switch out their pokemon), Leaf Tornado, Natural Gift, Air Slash, Solar Beam, Leaf Storm, and Synthesis (should you want to heal without using items)


and 4th natures to look for if your going to train a Tropius are those that will give you either high attack/special attack or high speed which include the following natures

Adamant, Bashful, Brave, Hardy, Hasty, Jolly, Lonely, Mild, Modest, Naive, Naughty, Quiet, Rash, Serious, and Timid

high defense/special defense are the following natures

Bold, Calm, Careful, Docile, Gentle, Impish, Lax, Quirky, Relaxed, and Sassy

I hope that this post was helpful in deciding how to set up a Tropius into your current team good luck with the battles everyone ^^