Dress however you are comfortable, with due reverence for the place and occasion. You’ll see congregants wearing jeans and others in business attire.
We do not require head coverings (kipot, yarmulkes), but many males and some females wear them. If it is your practice to wear one, by all means do so. There are extras on the bookshelf outside the coatroom if you forgot to bring yours.
Prayer shawls (tallitot) are not worn at Friday night services. Some people choose to wear them at morning services, but many do not. Again, we have some available on the bookshelf.