The first meaning of too is 'also' or 'besides'; the second is 'excessively' or 'extra'. Some people also use it to mean 'very'. Think of 'too' as being relevant when there is an increase of something, eg too hot, too challenging.
Use 'to' for expressing direction, place or position, eg I went to the beach. It is also used before a verb in the infinitive, eg to run.