Buchanan Street is one of the main shopping thoroughfares in Glasgow, and it's very accessible by various modes of transport.
Glasgow Airport (GLA) is the closest international airport. From there, you can:
Glasgow Queen Street and Glasgow Central are the two main train stations serving the city. Both are within walking distance to Buchanan Street or are just a short subway ride away.
Many bus services operate to and from Buchanan Bus Station which is located at the top of Buchanan Street.
Parking is available in multiple locations near Buchanan Street such as Buchanan Galleries and Concert Square car parks. Be aware that the street itself is pedestrianized.
The closest subway stations to Buchanan Street are Buchanan Street Station itself, at the northern end, and St Enoch Station at the southern end.
Buchanan Street is likely within walking distance from any city center accommodation, as it is situated at the heart of Glasgow.
Glasgow has a public bike hire scheme called Nextbike, with several hire stations around the city, including near Buchanan Street.
Note: If you are travelling on public transport, consider purchasing a day pass for convenience and better value.