I lots of have loose skin under my eyes, what is the best treatment? laser or bleph?

Either: Laser treatment with a fractional laser is a good non-invasive way to start. If this doesn't work then you can try fillers under the eyes (or PRP under the eyes). Again minimally invasive and also effective. Reserve a bleph for a last resort or if you have very severe skin laxity.

See a plastic surgeo: You need to see a plastic surgeon to get a proper answer to this question. Without being able to see and examine you in person, it is hard to answer this question in this setting.

Fine creepy skin can be treated with peels or lasers. Excess skin is better treated with blepharoplasty.