Activities for a 9 year old

[Finfintytint]

I am about to support a mum and their nine year old boy for a while. They will be staying with us in our home. My son is an adult and I haven’t entertained a nine year old for twenty years!
I know it depends on the individual child but what do they generally like to play with at the moment.
I will be getting plenty of art supplies and maybe some Lego.
is PlayMobil too young?
Any ideas please? I don’t want to overwhelm him or miss the mark age wise.

Yes, Playmobil is too young.
My DS is 11 and my DNephew is 8, rising 9.
They like:
Basketball
Skateboarding
Knex
Drawing cartoons and comic strips
Stunt kite and trick yo-yo
Fimo clay modelling
Learning card tricks
Gravitrax

DS has just turned 10, he likes;
Pokemon cards
Pokemon encyclopedia
Gravitrax
Anything with robotics to build (smyths have some inexpensive electronic/ robotic kits)
Cartoon drawing tutorials on YouTube
Card games
Flip book kit from amazon
Football
Boomerang
Swingball

Basketball hoop
Lego
DD loves colouring and crafts , DS hated it at that age.
Baking

My 9yo ds loves…
lego
scooting
going to the park
swimming
knex
gravitrax
climbing trees
drawing
board games like snakes and ladders/ludo
baking
LEGO!

Lots of great ideas, thank you.
knex, card games/ tricks sounds good.
Can get a basketball ring.
Baking would be great.
He is a non swimmer but I have already promised to help him with that.