A lazy eye is not a squint. They are separate.
A lazy eye is a eye that the brain has quit using, and only uses on eye to see, so the lazy eye loses vision because it is not being used.
You can have a squint without a lazy eye, but mostly they go together, but a squint could be focusing problems caused by astigmatism.
Yes go to the opticians, but you could also try your GP as you will need a referral, this can take up to three months unless there are other worrying signs.
As said it could be glasses, or patching or both if there is a squint.
If one is found then you will see a ophthalmic consultant, who will put drops in the eyes to establish the severity of the issues, and give a glasses prescription. The drops sting, but not for long.
Depending on the severity of the squint they may advise surgery, but not usually before trying glasses etc.
Good luck.