Note that you cannot say 'should to'. 'Should', like all modal verbs (must, can, may, will) is followed by the bare infinitive of the verb, with no 'to'. 'Have to' means 'must'. If you have to do something it is necessary. 'You have to show your passport at the border control'. 'Should' means it is advisable. If you say that someone should do something, you think that it's a good idea. 'You should read this book. I think that you'll find it useful'.

HAVE TO: "not a modal verb" >> I have to submit this proposal before noon. = I must submit this proposal before noon. -("Have to" in this sentence means "must.")- >> I have to go to the dentist as soon as possible. -(Necessity)- MUST: "a modal verb" >> I must go to the dentist as soon as possible. -(Necessity)- >> I must stop eating junk food. -(An obligation to myself)- >> You must always wear your company I.D. inside the office. -(Rule)- >> You must not talk to strangers. -(Prohibition)- >> You must have won the lottery. -(Assumption)- SHOULD: "weaker than MUST" >> You should be here before the start of the party. -(Obligation to someone)- >> You should eat more veggies. -(Friendly Advice / Suggestion)- >> Low-end smartphones in the Philippines shouldn't cost you more than a hundred dollars. -(Expectation about something)- :-)