I wouldn't disagree with much of the above (though I've read good reviews of Ibanez, and have liked the couple I have tried). But some additional thoughts:

Even if you plan to buy second hand, definitely go to a shop and try a few out to see what you like.

For example, I generally hear good things about Epiphone, but personally I have never liked any I played. In contrast (in terms of necks) I have liked pretty much all the Fender and Squier guitars I have played. But you might have the opposite experience. A lot of it is personal preference.

As suggested above, look at the style of guitar played by people you like - and use that as your starting point. And then play some to see which feel right to you.

In terms of amps, I really like the Vox AV15 and AV30. Not a modelling amp, but does have a good range of sounds from clean to Marshall style distortion. (Though apparently not so good for metal.) And they are not expensive. I had a much more expensive Roland Blues cube, but in the end sold it to buy another Vox. (I wanted 2 amps.)

I don't know the POD, but I think it does make sense to try a multi-effects unit, to experiment with. If you are happy with it, you can keep it. If you decide you want pedals later, playing with the multi-effects will help identify the pedals you want. (And if you don't want to buy loads of pedals, you can continue using the multi-effects for some of the lesser-used sounds.)

I have a few pedals, but also have a line 6 M9, which I find quite easy to use.

You ask about great guitars versus cheap guitars. I should say I don't have much experience of expensive guitars. But I'm not (yet) convinced of the need to get a very expensive guitar. I once played a £3000 Fender custom shop strat, and honestly did not prefer it to my mexican Fender, or my Squier vintage modified strat. (And indeed, I prefer my Squier to my Fender.) That said, I did have a Squier affinity, but sold that as I wasn't happy with the sound.

Ultimately though, if you buy second hand, don't worry about making a mistake. If you don't like it, you should be able to sell it for more or less what you bought it for and try again.