Grow it from seed, it seems easy enough... as an annual plant.. but I expect you've already found that out..

Sounds quite tasty from what I've been reading, as a herb...

Thank you for your reply, the main problem is that I have basically zero experience. Could you please summarize a few steps ? Thanks

If you have the seeds, you can direct sow in the garden, providing nighttime temps remain above 8C. Just make sure the soil is well drained but remains moist and the area receives plenty of sun. Directions should be on the seed package. The seeds should germinate within 3 weeks. Once they germinate and begin to grow, you should treat the same as you would basil.

Retail nurseries here sell perilla/shiso starts with their other herbs so you might want to hunt for those if growing already started plants would be easier than growing from seeds.

Thank you for the information, I got the seeds today, I saw on internet to soak some of them into water the night before so I'll pant them tomorrow, I just want to buy separate pot because I heard the plant is real invasive. Regarding the soil, can I buy just any normal from the shop ?

Unless you are growing in a pot you don't need to buy soil. Just plant it in the garden soil, after cultivation, obviously. If you're growing in a pot just buy a bag of multipurpose compost.