Excel Novice - Please help

Help me please! I am a complete excel novice, I work for an insurance broker in the UK and am looking to put together an excel spreadsheet that will help add together different scenarios in order to determine the correct premium to quote

I already have the data that needs to be input but am having trouble putting it together on excel

Example

I am looking for multiple outcomes on a single excel cell i.e If I put the age of the driver into Cell B2 (say between 15-20) than cell B3 would than equal 2.3 again if I entered the age of the driver into B2 saying they where aged between 26-30 than B3 would than equal 3.4

Eventually I would like to be able to multiply the answers to various questions separate I.e B3 X C3 + D3 = Premium I would quote

I hope this makes sense, and I appreciate you taking the time to look at this post (Hope you can help)