Why not begin by asking around – you might have a neighbour or work colleague who already attends church and might be pleased to take you along. Many churches will have events designed for visitors, particularly around the key Christian festivals like Christmas, Pentecost (Whit) etc. when you can usually pop in and get a feel for things.
There are many well-run and genuine independent churches around, but we live in a country of religious freedom, so there is no regulation or restriction on any religious group calling themselves “Christian”. It may be best therefore to stick, at least initially, with a mainstream denomination. (Church of England, Roman Catholic, Baptist, Methodist, United Reformed, Salvation Army, Independent Methodist) These titles are sometimes used by churches who are not affiliated to the national bodies behind them, so check out too that they belong to a wider organisation.
You can also ask around in the local community; healthy churches are usually well known and respected by other community groups. Also look for a church that seeks to work in partnership with other recognised Christian groups in the neighbourhood and in short, if you feel you are being put under undue pressure to believe or act in ways which you feel uncomfortable with, then perhaps it might be helpful to consider another local congregation.