If you look around on the map you will be able to see all the different icons such as Pokémon Stop and Pokémon Gyms. If you look closely you will be able to see a "leaf-effect", this indicates that there are Pokémon in that area.

Go there and you will encounter Pokémon.

I think you will find this link helpful: http://www.pokemongodb.net/2016/04/pokemon-go-types.html

It has a chart at the top showing what percentage of Kanto pokemon belong in each type. Below, it shows a list of all Pokemon in the game and after that there is a chart showing what type of Pokemon to expect in various Biomes.

Happy Hunting!

Possible Types

Normal

Boundaries, Landuse, Places, Roads, Transit, College, Commercial, Common, Footway, Hospital, Hotel, Library, Major Road, Minor Road, Pedestrian, Pitch, Playa, Recreation Area, Retail, Runway, School, Sports Center, Stadium, University

Grass

Landmass, Farm, Farmland, Farmyard, Forest, Garden, Golf Course, Grass, Meadow, Nature Reserve, Park, Path, Playground, Residential, Wood

Bug

Farm, Farmland, Farmyard, Forest, Garden, Golf Course, Grass, Nature Reserve, Park, Path, Playground, Wood

Water

Water, Basin, Canal, Dock, Drain, Glacier, Lake, Ocean, Reservoir, River, Riverbank, Stream

Flying

Farm, Farmland, Farmyard, Forest, Garden, Grass, Nature Reserve, Park, Wood

Rock

Building, Landmass, Highway, Industrial, Parking, Quarry, Railway, Urban Area

Ground

Landmass, Ditch, Land, Parking, Playground, Railway, Taxiway, Urban Area

Fairy

POIs, Cemetery, Place of Worship

Dark

Cemetery, Cinema, Theatre

Steel

Building, Railway

Dragon

POIs

Ghost

Cemetery

Ice

Glacier

Psychic

Hospital?

Electric

Industrial

Fire

Residential?

Poison

Wetland