It is not possible for tell you what likely sentence you will get for offences because sentencing considers a number of factors, including:
Maximum sentence of that offence
If you're charged with more than one offence, whether the judge wishes to sentence you concurrently (serving offences together) or cumulatively (serving offences one after the other)
Your prior criminal history
Your conduct at trial
Whether you pleaded guilty, and if so, at which stage of trial
Your conduct during police investigation
Your personal background, your family circumstances, any dependants, any explanations for you committing the offences etc.
As you can see from the list, we don't have enough information from you to assist on your sentencing. This list is not exhaustive and the judge may have consideration for any other factors (e.g. policy).
As for the maximum sentences, it's best to look at the sentence for drugs and that for firearms separately.
Drugs depend on:
Type of illegal drugs (ice)
Whether it was pure or mixed
Quantity of each type of drug (if mixed) and whether it was above trafficking/supply levels
Therefore, whether you're charged with just possession, trafficking or supply for drugs and whether trafficking is of a commercial or non-commercial level
For drugs, see "Drugs - father charged with trafficking". Note, this thread concerns Victorian legislation. However, the way drugs are classified and how sentencing for drugs is broken down is fairly similar across states and territories.
For the firearms, what charge is the police pursuing exactly?
Firearms are governed by the Firearms Act 1973 (WA). Section 19 of the Act states that the maximum sentence for a person in possession of 3 or more unlicensed firearms is 10 years imprisonment (s 19(1)(b)), or 14 years if they attempt to sell it (s 19(1aa)).