The thing about keyboards is that nowadays there's something for almost everyone. You don't have to do what others say, but you might try it, and it might work for you too. If it doesn't - that's fine, you will find something else. There's an absolute abundance of models in the most popular layouts - 60%, 65%, 75%, TKL, 1800, 100%, and there's more and more choice for the more niche sizes like 40%. And on the custom market there are even more things - like you want your numpad, but don't care about the F row? There's f-row-less 1800. You want your dedicated F keys but want to save horizontal space? There's 60% with an F row added.

For something new that you aren't used to, IMO it's a good idea to try it in a "reversible" manner - i.e. trying to stick with F keys on a layer on a board that still has dedicated F keys. For me this was arrow keys - I was previously on a 75% keyboard and I wanted to try home row navigation; I still had dedicated arrow keys, but I forced myself into using IJKL on a layer that I activate with my left pinkie - and ended up liking it (it's still what I'm using to this day). I agree with what others said about ortholinear - it's a bit better for placing a numpad on a layer; I personally have it so that 456 line up with JKL - this requires the minimum amount of hand movement and it works pretty well - maybe not as well as a dedicated numpad block because it's not physically separated - but I'd say it's 90% there.