Is FGO easy to pick up playing?

I think it is. The basics of the game are easy to learn, and you don't need much more for some time.
You can get surprisingly far by relying only on a strong support servant (at the beginning of every quest you can choose a servant from a list of servants of other people). Especially if it's the support servant of a friend, so you can use it's Noble Phantasm.

Though I would suggest you reroll until you get either a servant you like, or someone who is strong for your 4 star tutorial summon.
ed.: Or more than 1. You can get more than one 4 star servant in the tutorial summon.

Hey dude! :)
Yeah, FGO is pretty easy to pick up. I got started playing it about 3 months ago, and already I've gotten pretty proficient at playing it. Once you get the hang of the battle system, you will find most battles easily doable with the assistance of someone on your friends list.
I should warn you, though, that the summon rates are horrendously low. I have 2 5* servants, and that is super lucky for only 3 months.
I made a post about the summon rates on the Heroes side today, here's the link: https://fireemblem.gamepress.gg/q-a/little-thought-relation-and-generosity

Yeah, of course, as long as you could handle the salt and know what you are doing, it is pretty easy.
Tip: use everyone you can use and don't be overreliant on golds and friend's supports

The battle system is pretty easy to pick up, but there are some tips

Use servants that are lower rarity: They are lower cost in team comps, which is necessary considering that even at high levels, it can be difficult to balance costs, and that some are great and hold up to even gold stars, such as Mash (defensive tank that, because of no cost in teams, allows for more flexible team comps and to take damage in place of some more heavy hitters), Anderson (Not as good as the Tamamo Waver Merlin trio, is a decently strong support servant that can heal and boost stats), and Cu Chulainn [lancer] (basically unkillable)

Research the servants you get: I got Stheno (notoriously useless) and put too many resources into her because I did not know this, and assumed all gold stars were good, moral of the story: research the purpose of a servant. Even if you get a highly coveted servant, putting them in a team that makes no sense with them (like putting a buster based servant into an arts team) would probably impede you.

Friends: Get friends. Early on especially, a strong support will help you get through the story. This may apply to events less though, and the later chapters (Okeanos onward probably), as they tend to be more difficult, and that only a few servants can run through those chapters by themselves, and even then, it depends on luck.

Farm for QP and EXP: In between events and new story releases you will probably have some downtime. Use this to grind up EXP and QP, this will be needed for future servants, even if everyone you have is at a good level right now

Just have fun. Interact with the community, make fanart or analysis or just share your opinion (or gatcha salt)

oh. and try not to go broke