Probably not, a simple dimension door might do it
You can simply teleport there with dimension door through Globe of Invulnerability, which does not block it.
Wether Prismatic Wall would stop you is unresolved, there are highly upvoted answers for both sides. It is not an obstacle that you cannot see inside, as you do not need to see the target space with dimension door, but the question is if you can select a spot in there as the target area. My take is that the argument this does not work as you cannot target a spot is flawed: you also cannot target any other spot you do not have a line of effect to, and it is generally understood that you still can dimension door onto the other side of walls or doors. So my take is, you get in. If you do, you are not passing through the wall, so you take none of the ill effects from the various layers.
The spell is only 4th level, and allows you to take along a barbarian or other smasher with high Con. This is useful as you both still have to save against being blinded when you arrive due to being close to the wall, and you want to avoid being blinded because it imposes disadvantage to attacks.
With high to hit bonus the smasher can attack and hit the caster, and even a shield will not make them safe from that. If as a barbarian he attacks recklessly, the advantage essentially will offset shield. Once they are hit, they have to make a concentration check for their globe, too.
For your side questions (which you probably should remove, as they are really unrelated to the main question):
There is no way to concentrate on more than one concentration spell, but there is a workaround in putting such spells into a glyph of warding if they are legal for being put in there: then, for example for spells that conjure creatures, the glyph will take care of the concentration.
Globe of Invulnerability does not care about allied or friendly or hostile creatures, it cares about where the caster is when casting the spell:
Any spell of 5th level or lower cast from outside the barrier can't affect creatures or objects within it, even if the spell is cast using a higher level spell slot
Once you are inside the barrier, you can cast at the creator of the globe without a problem.